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path: root/drivers/pci/pcie/aspm.c
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2020-08-21PCI/ASPM: Add missing newline in sysfs 'policy'Xiongfeng Wang1-0/+1
[ Upstream commit 3167e3d340c092fd47924bc4d23117a3074ef9a9 ] When I cat ASPM parameter 'policy' by sysfs, it displays as follows. Add a newline for easy reading. Other sysfs attributes already include a newline. [root@localhost ~]# cat /sys/module/pcie_aspm/parameters/policy [default] performance powersave powersupersave [root@localhost ~]# Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") Link: https://lore.kernel.org/r/1594972765-10404-1-git-send-email-wangxiongfeng2@huawei.com Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-25PCI/ASPM: Allow ASPM on links to PCIe-to-PCI/PCI-X BridgesKai-Heng Feng1-10/+0
[ Upstream commit 66ff14e59e8a30690755b08bc3042359703fb07a ] 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") added the ability for Linux to enable ASPM, but for some undocumented reason, it didn't enable ASPM on links where the downstream component is a PCIe-to-PCI/PCI-X Bridge. Remove this exclusion so we can enable ASPM on these links. The Dell OptiPlex 7080 mentioned in the bugzilla has a TI XIO2001 PCIe-to-PCI Bridge. Enabling ASPM on the link leading to it allows the Intel SoC to enter deeper Package C-states, which is a significant power savings. [bhelgaas: commit log] Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207571 Link: https://lore.kernel.org/r/20200505173423.26968-1-kai.heng.feng@canonical.com Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-05-02PCI/ASPM: Allow re-enabling Clock PMHeiner Kallweit1-7/+11
[ Upstream commit 35efea32b26f9aacc99bf07e0d2cdfba2028b099 ] Previously Clock PM could not be re-enabled after being disabled by pci_disable_link_state() because clkpm_capable was reset. Change this by adding a clkpm_disable field similar to aspm_disable. Link: https://lore.kernel.org/r/4e8a66db-7d53-4a66-c26c-f0037ffaa705@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-24PCI/ASPM: Clear the correct bits when enabling L1 substatesYicong Yang1-2/+2
commit 58a3862a10a317a81097ab0c78aecebabb1704f5 upstream. In pcie_config_aspm_l1ss(), we cleared the wrong bits when enabling ASPM L1 Substates. Instead of the L1.x enable bits (PCI_L1SS_CTL1_L1SS_MASK, 0xf), we cleared the Link Activation Interrupt Enable bit (PCI_L1SS_CAP_L1_PM_SS, 0x10). Clear the L1.x enable bits before writing the new L1.x configuration. [bhelgaas: changelog] Fixes: aeda9adebab8 ("PCI/ASPM: Configure L1 substate settings") Link: https://lore.kernel.org/r/1584093227-1292-1-git-send-email-yangyicong@hisilicon.com Signed-off-by: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.11+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-25PCI: Work around Pericom PCIe-to-PCI bridge Retrain Link erratumStefan Mätje1-0/+9
commit 4ec73791a64bab25cabf16a6067ee478692e506d upstream. Due to an erratum in some Pericom PCIe-to-PCI bridges in reverse mode (conventional PCI on primary side, PCIe on downstream side), the Retrain Link bit needs to be cleared manually to allow the link training to complete successfully. If it is not cleared manually, the link training is continuously restarted and no devices below the PCI-to-PCIe bridge can be accessed. That means drivers for devices below the bridge will be loaded but won't work and may even crash because the driver is only reading 0xffff. See the Pericom Errata Sheet PI7C9X111SLB_errata_rev1.2_102711.pdf for details. Devices known as affected so far are: PI7C9X110, PI7C9X111SL, PI7C9X130. Add a new flag, clear_retrain_link, in struct pci_dev. Quirks for affected devices set this bit. Note that pcie_retrain_link() lives in aspm.c because that's currently the only place we use it, but this erratum is not specific to ASPM, and we may retrain links for other reasons in the future. Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu> [bhelgaas: apply regardless of CONFIG_PCIEASPM] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-25PCI: Factor out pcie_retrain_link() functionStefan Mätje1-16/+24
commit 86fa6a344209d9414ea962b1f1ac6ade9dd7563a upstream. Factor out pcie_retrain_link() to use for Pericom Retrain Link quirk. No functional change intended. Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13PCI/ASPM: Fix link_state teardown on device removalLukas Wunner1-1/+1
commit aeae4f3e5c38d47bdaef50446dc0ec857307df68 upstream. Upon removal of the last device on a bus, the link_state of the bridge leading to that bus is sought to be torn down by having pci_stop_dev() call pcie_aspm_exit_link_state(). When ASPM was originally introduced by commit 7d715a6c1ae5 ("PCI: add PCI Express ASPM support"), it determined whether the device being removed is the last one by calling list_empty() on the bridge's subordinate devices list. That didn't work because the device is only removed from the list slightly later in pci_destroy_dev(). Commit 3419c75e15f8 ("PCI: properly clean up ASPM link state on device remove") attempted to fix it by calling list_is_last(), but that's not correct either because it checks whether the device is at the *end* of the list, not whether it's the last one *left* in the list. If the user removes the device which happens to be at the end of the list via sysfs but other devices are preceding the device in the list, the link_state is torn down prematurely. The real fix is to move the invocation of pcie_aspm_exit_link_state() to pci_destroy_dev() and reinstate the call to list_empty(). Remove a duplicate check for dev->bus->self because pcie_aspm_exit_link_state() already contains an identical check. Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: stable@vger.kernel.org # v2.6.26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-09PCI/ASPM: Deal with missing root ports in link state handlingArd Biesheuvel1-2/+6
commit ee8bdfb6568d86bb93f55f8d99c4c643e77304ee upstream. Even though it is unconventional, some PCIe host implementations omit the root ports entirely, and simply consist of a host bridge (which is not modeled as a device in the PCI hierarchy) and a link. When the downstream device is an endpoint, our current code does not seem to mind this unusual configuration. However, when PCIe switches are involved, the ASPM code assumes that any downstream switch port has a parent, and blindly dereferences the bus->parent->self field of the pci_dev struct to chain the downstream link state to the link state of the root port. Given that the root port is missing, the link is not modeled at all, and nor is the link state, and attempting to access it results in a NULL pointer dereference and a crash. Avoid this by allowing the link state chain to terminate at the downstream port if no root port exists. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30PCI/ASPM: Use correct capability pointer to program LTR_L1.2_THRESHOLDBjorn Helgaas1-1/+1
commit c00054f540bf81e592e1fee709b0bdbf20f478b5 upstream. Previously we programmed the LTR_L1.2_THRESHOLD in the parent (upstream) device using the capability pointer of the *child* (downstream) device, which corrupted some random word of the parent's config space. Use the parent's L1 SS capability pointer to program its LTR_L1.2_THRESHOLD. Fixes: aeda9adebab8 ("PCI/ASPM: Configure L1 substate settings") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Vidya Sagar <vidyas@nvidia.com> CC: Rajat Jain <rajatja@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30PCI/ASPM: Account for downstream device's Port Common_Mode_Restore_TimeBjorn Helgaas1-1/+1
commit 94ac327e043ee40d7fc57b54541da50507ef4e99 upstream. Every Port that supports the L1.2 substate advertises its Port Common_Mode_Restore_Time, i.e., the time the Port requires to re-establish common mode when exiting L1.2 (see PCIe r3.1, sec 7.33.2). Per sec 5.5.3.3.1, when exiting L1.2, the Downstream Port (the device at the upstream end of the link) must send TS1 training sequences for at least T(COMMONMODE) after it detects electrical idle exit on the Link. We want this to be long enough for both ends of the Link, so we should set it to the maximum of the Port Common_Mode_Restore_Time for the upstream and downstream components on the Link. Previously we only looked at the Port Common_Mode_Restore_Time of the upstream device, so if the downstream device required more time, we didn't program the upstream device's T(COMMONMODE) correctly. Fixes: f1f0366dd6be ("PCI/ASPM: Calculate and save the L1.2 timing parameters") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Vidya Sagar <vidyas@nvidia.com> Acked-by: Rajat Jain <rajatja@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-07PCI/ASPM: Always set link->downstream to avoid NULL dereference on removeYinghai Lu1-3/+2
We call pcie_aspm_exit_link_state() when we remove a device. If the device is the last PCIe function to be removed below a bridge and the bridge has an ASPM link_state struct, we disable ASPM on the link. Disabling ASPM requires link->downstream (used in pcie_config_aspm_link()). We previously set link->downstream in pcie_aspm_cap_init(), but only if the device was not blacklisted. Removing the blacklisted device caused a NULL pointer dereference in the pcie_aspm_exit_link_state() -> pcie_config_aspm_link() path: # echo 1 > /sys/bus/pci/devices/0000\:0b\:00.0/remove ... BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 IP: pcie_config_aspm_link+0x5d/0x2b0 Call Trace: pcie_aspm_exit_link_state+0x75/0x130 pci_stop_bus_device+0xa4/0xb0 pci_stop_and_remove_bus_device_locked+0x1a/0x30 remove_store+0x50/0x70 dev_attr_store+0x18/0x30 sysfs_kf_write+0x44/0x60 kernfs_fop_write+0x10e/0x190 __vfs_write+0x28/0x110 ? rcu_read_lock_sched_held+0x5d/0x80 ? rcu_sync_lockdep_assert+0x2c/0x60 ? __sb_start_write+0x173/0x1a0 ? vfs_write+0xb3/0x180 vfs_write+0xc4/0x180 SyS_write+0x49/0xa0 do_syscall_64+0xa6/0x1c0 entry_SYSCALL64_slow_path+0x25/0x25 ---[ end trace bd187ee0267df5d9 ]--- To avoid this, set link->downstream in alloc_pcie_link_state(), so every pcie_link_state structure has a valid link->downstream pointer. [bhelgaas: changelog] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rajat Jain <rajatja@google.com> CC: stable@vger.kernel.org
2017-02-23Merge tag 'pci-v4.11-changes' of ↵Linus Torvalds1-13/+278
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: - add ASPM L1 substate support - enable PCIe Extended Tags when supported - configure PCIe MPS settings on iProc, Versatile, X-Gene, and Xilinx - increase VPD access timeout - add ACS quirks for Intel Union Point, Qualcomm QDF2400 and QDF2432 - use new pci_irq_alloc_vectors() in more drivers - fix MSI affinity memory leak - remove unused MSI interfaces and update documentation - remove unused AER .link_reset() callback - avoid pci_lock / p->pi_lock deadlock seen with perf - serialize sysfs enable/disable num_vfs operations - move DesignWare IP from drivers/pci/host/ to drivers/pci/dwc/ and refactor so we can support both hosts and endpoints - add DT ECAM-like support for HiSilicon Hip06/Hip07 controllers - add Rockchip system power management support - add Thunder-X cn81xx and cn83xx support - add Exynos 5440 PCIe PHY support * tag 'pci-v4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (93 commits) PCI: dwc: Remove dependency of designware on CONFIG_PCI PCI: dwc: Add CONFIG_PCIE_DW_HOST to enable PCI dwc host PCI: dwc: Split pcie-designware.c into host and core files PCI: dwc: designware: Fix style errors in pcie-designware.c PCI: dwc: designware: Parse "num-lanes" property in dw_pcie_setup_rc() PCI: dwc: all: Split struct pcie_port into host-only and core structures PCI: dwc: designware: Get device pointer at the start of dw_pcie_host_init() PCI: dwc: all: Rename cfg_read/cfg_write to read/write PCI: dwc: all: Use platform_set_drvdata() to save private data PCI: dwc: designware: Move register defines to designware header file PCI: dwc: Use PTR_ERR_OR_ZERO to simplify code PCI: dra7xx: Group PHY API invocations PCI: dra7xx: Enable MSI and legacy interrupts simultaneously PCI: dra7xx: Add support to force RC to work in GEN1 mode PCI: dra7xx: Simplify probe code with devm_gpiod_get_optional() PCI: Move DesignWare IP support to new drivers/pci/dwc/ directory PCI: exynos: Support the PHY generic framework Documentation: binding: Modify the exynos5440 PCIe binding phy: phy-exynos-pcie: Add support for Exynos PCIe PHY Documentation: samsung-phy: Add exynos-pcie-phy binding ...
2017-02-15PCI/ASPM: Add comment about L1 substate latencyRajat Jain1-0/+8
Since the exit latencies for L1 substates are not advertised by a device, it is not clear in spec how to do a L1 substate exit latency check. We assume that the L1 exit latencies advertised by a device include L1 substate latencies (and hence do not do any check). If that is not true, we should do some sort of check here. (I'm not clear about what that check should like currently. I'd be glad to take up any suggestions). Signed-off-by: Rajat Jain <rajatja@google.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-02-15PCI/ASPM: Configure L1 substate settingsRajat Jain1-2/+104
Configure the L1 substate settings on the upstream and downstream devices, while taking care of the rules dictated by the PCIe spec. [bhelgaas: drop "inline"] Signed-off-by: Rajat Jain <rajatja@google.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-02-15PCI/ASPM: Calculate and save the L1.2 timing parametersRajat Jain1-0/+79
Calculate and save the timing parameters that need to be programmed if we need to enable L1.2 substates later. We use the same logic (and a constant value for 1 of the parameters) as used by Intel's coreboot: https://www.coreboot.org/pipermail/coreboot-gerrit/2015-March/021134.html https://review.coreboot.org/#/c/8832/ Signed-off-by: Rajat Jain <rajatja@google.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-02-15PCI/ASPM: Read and set up L1 substate capabilitiesRajat Jain1-1/+58
The PCIe spec (r3.1, sec 7.33) says the L1 PM Substates Capability may be implemented only in function 0. Read the L1 substate capability structures of upstream and downstream components of the link and set it up in the device structure. [bhelgaas: add specific spec reference] Signed-off-by: Rajat Jain <rajatja@google.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-02-15PCI/ASPM: Add support for L1 substatesRajat Jain1-10/+29
Add support for ASPM L1 substates. For details about L1 substates, see the PCIe r3.1 spec, which includes the ECN below in secs 5.5 and 7.33. Add macros for the 4 new L1 substates, and add a new ASPM "POWER_SUPERSAVE" policy that can be used to enable L1 substates on a system if desired. The new policy is in a sense, a superset of the existing POWERSAVE policy. The 4 policies are now: DEFAULT: Reads and uses whatever ASPM states BIOS enabled PERFORMANCE: Everything except L0 disabled. POWERSAVE: L0s and L1 enabled (but not L1 substates) POWER_SUPERSAVE: L0s + L1 + L1 substates also enabled [bhelgaas: add PCIe r3.1 spec reference] Link: https://pcisig.com/sites/default/files/specification_documents/ECN_L1_PM_Substates_with_CLKREQ_31_May_2013_Rev10a.pdf Signed-off-by: Rajat Jain <rajatja@google.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2017-01-28PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchiesBjorn Helgaas1-6/+13
In a struct pcie_link_state, link->root points to the pcie_link_state of the root of the PCIe hierarchy. For the topmost link, this points to itself (link->root = link). For others, we copy the pointer from the parent (link->root = link->parent->root). Previously we recognized that Root Ports originated PCIe hierarchies, but we treated PCI/PCI-X to PCIe Bridges as being in the middle of the hierarchy, and when we tried to copy the pointer from link->parent->root, there was no parent, and we dereferenced a NULL pointer: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820 Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just like Root Ports do, so link->root for these devices should also point to itself. Fixes: 51ebfc92b72b ("PCI: Enumerate switches below PCI-to-PCIe bridges") Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411 Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181 Tested-by: lists@ssl-mail.com Tested-by: Jayachandran C. <jnair@caviumnetworks.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
2016-12-08PCI/ASPM: Don't retrain link if ASPM not possibleDavid Daney1-2/+16
Some (defective) PCIe devices are not able to reliably do link retraining. Check to see if ASPM is possible between link partners before configuring common clocking, and doing the resulting link retraining. If ASPM is not possible, there is no reason to risk losing access to a device due to an unnecessary link retraining. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-11-15PCI/ASPM: Use permission-specific DEVICE_ATTR variantsJulia Lawall1-2/+2
Use DEVICE_ATTR_RW for read-write attributes. This simplifies the source code, improves readability, and reduces the chance of inconsistencies. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @rw@ declarer name DEVICE_ATTR; identifier x,x_show,x_store; @@ DEVICE_ATTR(x, \(0644\|S_IRUGO|S_IWUSR\), x_show, x_store); @script:ocaml@ x << rw.x; x_show << rw.x_show; x_store << rw.x_store; @@ if not (x^"_show" = x_show && x^"_store" = x_store) then Coccilib.include_match false @@ declarer name DEVICE_ATTR_RW; identifier rw.x,rw.x_show,rw.x_store; @@ - DEVICE_ATTR(x, \(0644\|S_IRUGO|S_IWUSR\), x_show, x_store); + DEVICE_ATTR_RW(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-06-11PCI/ASPM: Remove redundant check of pcie_set_clkpmShawn Lin1-1/+1
Without supporting clock PM capable, if we want to disable clkpm, we don't need this extra check as it must already be zero for the enable argument. And it's the same for enabling clkpm here. So let's remove this check. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-12-03PCI/ASPM: Make sysfs link_state_store() consistent with link_state_show()Andy Lutomirski1-11/+5
If CONFIG_PCIEASPM_DEBUG is set, then PCI devices have a link_state attribute. Reading that attribute shows the state as a bit mask: 1 means L0S upstream, 2 means L0S downstream, and 4 means L1. Oddly, writing to link_state is inconsistent and gets translated, leading to mysterious results in which the value you store isn't comparable the value you load back out. Fix it by making link_state_store() match link_state_show(). [bhelgaas: Check "aspm_disabled" *before* validating input. When "aspm_disabled" is set, this changes the error for invalid input from -EINVAL to -EPERM.] Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-06-10PCI/ASPM: Simplify Clock Power Management settingBjorn Helgaas1-8/+5
Update the Link Control Enable Clock Power Management bit the same way we update the ASPM Control bits, with a single call of pcie_capability_clear_and_set_word(). No functional change; this just makes both paths use the same style. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-26PCI/ASPM: Use dev->has_secondary_link to find downstream linksYijing Wang1-6/+10
We allocate pcie_link_state for the component at the upstream end of a Link. Previously we did this by allocating pcie_link_state for Root Ports and Downstream Ports. This works fine for the typical topology: 00:1c.0 Root Port [bridge to bus 02] 02:00.0 Upstream Port [bridge to bus 03] 03:00.0 Downstream Port [bridge to bus 04] 04:00.0 Endpoint or Switch Port However, it is possible to have a Root Port connected to a Downstream Port instead of an Upstream Port, as in Robert White's ATCA system: 00:1c.0 Root Port [bridge to bus 02] 02:00.0 Downstream Port [bridge to bus 03] 03:01.0 Downstream Port [bridge to bus 04] 04:00.0 Endpoint or Switch Port In this topology, we wrongly allocated pcie_link_state for the 02:00.0 Downstream Port, which is actually the *downstream* end of a link. This led to the following NULL pointer dereference when we tried to connect this link into the tree of links starting at the 00:1c.0 Root Port: BUG: unable to handle kernel NULL pointer dereference at 0000000000000088 IP: [<ffffffff81550324>] pcie_aspm_init_link_state+0x744/0x850 Hardware name: Kontron B3001/B3001, BIOS 4.6.3 08/07/2012 Call Trace: [<ffffffff8153b865>] pci_scan_slot+0xd5/0x120 [<ffffffff8153ca1d>] pci_scan_child_bus+0x2d/0xd0 ... Instead of relying on the component type to identify the upstream end of a link, use the "dev->has_secondary_link" field. This means it's now possible for an Upstream Port to have a link on its secondary side, so alloc_pcie_link_state() needs to connect links originating from both Upstream and Downstream Ports into the tree. [bhelgaas: changelog, add comment] Link: https://bugzilla.kernel.org/show_bug.cgi?id=94361 Link: http://lkml.kernel.org/r/54EB81B2.4050904@pobox.com Reported-by: Robert White <rwhite@pobox.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-20PCI/ASPM: Remove redundant PCIe port type checkingYijing Wang1-15/+4
We decide in alloc_pcie_link_state() whether to allocate a pcie_link_state for a device. After that, it's sufficient to check pdev->link_state. We don't need to check the PCIe port type again. Remove the redundant PCIe port type checking. [bhelgaas: changelog] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-05-20PCI/ASPM: Drop __pci_disable_link_state() useless "force" parameterBjorn Helgaas1-5/+4
After 387d37577fdd ("PCI: Don't clear ASPM bits when the FADT declares it's unsupported"), the "force" parameter to __pci_disable_link_state() is always "false". Remove the "force" parameter and assume it's always false. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-04-09PCI: Don't clear ASPM bits when the FADT declares it's unsupportedMatthew Garrett1-18/+0
Communications with a hardware vendor confirm that the expected behaviour on systems that set the FADT ASPM disable bit but which still grant full PCIe control is for the OS to leave any BIOS configuration intact and refuse to touch the ASPM bits. This mimics the behaviour of Windows. Signed-off-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2015-01-09PCI/ASPM: Use standard parsing functions for sysfs settersChris J Arges1-5/+7
The functions link_state_store() and clk_ctl_store() had just subtracted ASCII '0' from input which could lead to undesired results. Instead, use Linux string functions to safely parse input. [bhelgaas: check kstrtouint() return value] Signed-off-by: Chris J Arges <chris.j.arges@canonical.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-01-13PCI: Remove unused pcie_aspm_enabled()Stephen Hemminger1-12/+0
My philosophy is unused code is dead code. And dead code is subject to bit rot and is a likely source of bugs. Use it or lose it. This reverts part of 3e1b16002af2 ("ACPI/PCI: PCIe ASPM _OSC support capabilities called when root bridge added"), removing this interface: pcie_aspm_enabled() [bhelgaas: split to separate patch] Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Andrew Patterson <andrew.patterson@hp.com>
2013-11-14PCI: Fix whitespace, capitalization, and spelling errorsBjorn Helgaas1-1/+1
Fix whitespace, capitalization, and spelling errors. No functional change. I know "busses" is not an error, but "buses" was more common, so I used it consistently. Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus()) Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-28PCI: Fix kerneldoc for pci_disable_link_state()Yijing Wang1-4/+9
Fix kerneldoc for pci_disable_link_state(). [bhelgaas: expand comment, fix typos] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-05-21PCI/ASPM: Warn when driver asks to disable ASPM, but we can't do itBjorn Helgaas1-3/+13
Some devices have hardware problems related to using ASPM. Drivers for these devices use pci_disable_link_state() to prevent their device from entering L0s or L1. But on platforms where the OS doesn't have permission to manage ASPM, pci_disable_link_state() doesn't actually disable ASPM. Windows has a similar mechanism ("PciASPMOptOut"), and when the OS doesn't have control of ASPM, it doesn't actually disable ASPM either. This patch just adds a warning in dmesg about the fact that pci_disable_link_state() is doing nothing. Reported-by: Emmanuel Grumbach <egrumbach@gmail.com> Reference: https://lkml.kernel.org/r/CANUX_P3F5YhbZX3WGU-j1AGpbXb_T9Bis2ErhvKkFMtDvzatVQ@mail.gmail.com Reference: https://bugzilla.kernel.org/show_bug.cgi?id=57331 Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-02-26Merge tag 'pci-v3.9-changes' of ↵Linus Torvalds1-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI changes from Bjorn Helgaas: "Host bridge hotplug - Major overhaul of ACPI host bridge add/start (Rafael Wysocki, Yinghai Lu) - Major overhaul of PCI/ACPI binding (Rafael Wysocki, Yinghai Lu) - Split out ACPI host bridge and ACPI PCI device hotplug (Yinghai Lu) - Stop caching _PRT and make independent of bus numbers (Yinghai Lu) PCI device hotplug - Clean up cpqphp dead code (Sasha Levin) - Disable ARI unless device and upstream bridge support it (Yijing Wang) - Initialize all hot-added devices (not functions 0-7) (Yijing Wang) Power management - Don't touch ASPM if disabled (Joe Lawrence) - Fix ASPM link state management (Myron Stowe) Miscellaneous - Fix PCI_EXP_FLAGS accessor (Alex Williamson) - Disable Bus Master in pci_device_shutdown (Konstantin Khlebnikov) - Document hotplug resource and MPS parameters (Yijing Wang) - Add accessor for PCIe capabilities (Myron Stowe) - Drop pciehp suspend/resume messages (Paul Bolle) - Make pci_slot built-in only (not a module) (Jiang Liu) - Remove unused PCI/ACPI bind ops (Jiang Liu) - Removed used pci_root_bus (Bjorn Helgaas)" * tag 'pci-v3.9-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (51 commits) PCI/ACPI: Don't cache _PRT, and don't associate them with bus numbers PCI: Fix PCI Express Capability accessors for PCI_EXP_FLAGS ACPI / PCI: Make pci_slot built-in only, not a module PCI/PM: Clear state_saved during suspend PCI: Use atomic_inc_return() rather than atomic_add_return() PCI: Catch attempts to disable already-disabled devices PCI: Disable Bus Master unconditionally in pci_device_shutdown() PCI: acpiphp: Remove dead code for PCI host bridge hotplug PCI: acpiphp: Create companion ACPI devices before creating PCI devices PCI: Remove unused "rc" in virtfn_add_bus() PCI: pciehp: Drop suspend/resume ENTRY messages PCI/ASPM: Don't touch ASPM if forcibly disabled PCI/ASPM: Deallocate upstream link state even if device is not PCIe PCI: Document MPS parameters pci=pcie_bus_safe, pci=pcie_bus_perf, etc PCI: Document hpiosize= and hpmemsize= resource reservation parameters PCI: Use PCI Express Capability accessor PCI: Introduce accessor to retrieve PCIe Capabilities Register PCI: Put pci_dev in device tree as early as possible PCI: Skip attaching driver in device_add() PCI: acpiphp: Keep driver loaded even if no slots found ...
2013-02-02PCI/ASPM: Don't touch ASPM if forcibly disabledJoe Lawrence1-0/+3
Don't allocate and track PCIe ASPM state when "pcie_aspm=off" is specified on the kernel command line. Based-on-patch-from: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: David Bulkow <david.bulkow@stratus.com> Acked-by: Myron Stowe <myron.stowe@redhat.com>
2013-02-02PCI/ASPM: Deallocate upstream link state even if device is not PCIeMyron Stowe1-4/+1
On PCI bus hotplug removal, pcie_aspm_exit_link_state() can potentially skip parent devices that have link_state allocated. Instead of exiting early if a given device is not PCIe, check whether or not the device's parent has link_state allocated. This enables pcie_aspm_exit_link_state() to properly clean up parent link_state when the last function in a slot might not be PCIe. Reported-by: Joe Lawrence <joe.lawrence@stratus.com> Tested-by: Joe Lawrence <joe.lawrence@stratus.com> Signed-off-by: Myron Stowe <myron.stowe@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2013-01-15PCI: Allow pcie_aspm=force even when FADT indicates it is unsupportedColin Ian King1-0/+3
Right now using pcie_aspm=force will not enable ASPM if the FADT indicates ASPM is unsupported. However, the semantics of force should probably allow for this, especially as they did before 3c076351c4 ("PCI: Rework ASPM disable code") This patch just skips the clearing of any ASPM setup that the firmware has carried out on this bus if pcie_aspm=force is being used. Reference: http://bugs.launchpad.net/bugs/962038 Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org
2012-12-07Merge branch 'pci/bjorn-pcie-cap' into nextBjorn Helgaas1-5/+6
* pci/bjorn-pcie-cap: ath9k: Use standard #defines for PCIe Capability ASPM fields iwlwifi: Use standard #defines for PCIe Capability ASPM fields iwlwifi: collapse wrapper for pcie_capability_read_word() iwlegacy: Use standard #defines for PCIe Capability ASPM fields iwlegacy: collapse wrapper for pcie_capability_read_word() cxgb3: Use standard #defines for PCIe Capability ASPM fields PCI: Add standard PCIe Capability Link ASPM field names PCI/portdrv: Use PCI Express Capability accessors PCI: Use standard PCIe Capability Link register field names PCI: Add and use standard PCI-X Capability register names
2012-12-07PCI: Add standard PCIe Capability Link ASPM field namesBjorn Helgaas1-5/+6
Add standard #defines for ASPM fields in PCI Express Link Capability and Link Control registers. Previously we used PCIE_LINK_STATE_L0S and PCIE_LINK_STATE_L1 directly, but these are defined for the Linux ASPM interfaces, e.g., pci_disable_link_state(), and only coincidentally match the actual register bits. PCIE_LINK_STATE_CLKPM, also part of that interface, does not match the register bit. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
2012-11-08PCI: Convert dev_printk(KERN_<LEVEL> to dev_<level>(Joe Perches1-5/+2
dev_<level> calls take less code than dev_printk(KERN_<LEVEL> and reducing object size is good. Coalesce formats for easier grep. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-08-23PCI/ASPM: Use PCI Express Capability accessorsJiang Liu1-51/+26
Use PCI Express Capability access functions to simplify PCIe ASPM. Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-08-23PCI: Introduce pci_pcie_type(dev) to replace pci_dev->pcie_typeYijing Wang1-21/+21
Introduce an inline function pci_pcie_type(dev) to extract PCIe device type from pci_dev->pcie_flags_reg field, and prepare for removing pci_dev->pcie_type. Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-03-31ASPM: Fix pcie devices with non-pcie childrenMatthew Garrett1-3/+10
Since 3.2.12 and 3.3, some systems are failing to boot with a BUG_ON. Some other systems using the pata_jmicron driver fail to boot because no disks are detected. Passing pcie_aspm=force on the kernel command line works around it. The cause: commit 4949be16822e ("PCI: ignore pre-1.1 ASPM quirking when ASPM is disabled") changed the behaviour of pcie_aspm_sanity_check() to always return 0 if aspm is disabled, in order to avoid cases where we changed ASPM state on pre-PCIe 1.1 devices. This skipped the secondary function of pcie_aspm_sanity_check which was to avoid us enabling ASPM on devices that had non-PCIe children, causing trouble later on. Move the aspm_disabled check so we continue to honour that scenario. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=42979 and http://bugs.debian.org/665420 Reported-by: Romain Francoise <romain@orebokech.com> # kernel panic Reported-by: Chris Holland <bandidoirlandes@gmail.com> # disk detection trouble Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: stable@vger.kernel.org Tested-by: Hatem Masmoudi <hatem.masmoudi@gmail.com> # Dell Latitude E5520 Tested-by: janek <jan0x6c@gmail.com> # pata_jmicron with JMB362/JMB363 [jn: with more symptoms in log message] Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-24Merge branch 'linux-next' of ↵Linus Torvalds1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci Pull PCI changes (including maintainer change) from Jesse Barnes: "This pull has some good cleanups from Bjorn and Yinghai, as well as some more code from Yinghai to better handle resource re-allocation when enabled. There's also a new initcall_debug feature from Arjan which will print out quirk timing information to help identify slow quirks for fixing or refinement (Yinghai sent in a few patches to do just that once the new debug code landed). Beyond that, I'm handing off PCI maintainership to Bjorn Helgaas. He's been a core PCI and Linux contributor for some time now, and has kindly volunteered to take over. I just don't feel I have the time for PCI review and work that it deserves lately (I've taken on some other projects), and haven't been as responsive lately as I'd like, so I approached Bjorn asking if he'd like to manage things. He's going to give it a try, and I'm confident he'll do at least as well as I have in keeping the tree managed, patches flowing, and keeping things stable." Fix up some fairly trivial conflicts due to other cleanups (mips device resource fixup cleanups clashing with list handling cleanup, ppc iseries removal clashing with pci_probe_only cleanup etc) * 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci: (112 commits) PCI: Bjorn gets PCI hotplug too PCI: hand PCI maintenance over to Bjorn Helgaas unicore32/PCI: move <asm-generic/pci-bridge.h> include to asm/pci.h sparc/PCI: convert devtree and arch-probed bus addresses to resource powerpc/PCI: allow reallocation on PA Semi powerpc/PCI: convert devtree bus addresses to resource powerpc/PCI: compute I/O space bus-to-resource offset consistently arm/PCI: don't export pci_flags PCI: fix bridge I/O window bus-to-resource conversion x86/PCI: add spinlock held check to 'pcibios_fwaddrmap_lookup()' PCI / PCIe: Introduce command line option to disable ARI PCI: make acpihp use __pci_remove_bus_device instead PCI: export __pci_remove_bus_device PCI: Rename pci_remove_behind_bridge to pci_stop_and_remove_behind_bridge PCI: Rename pci_remove_bus_device to pci_stop_and_remove_bus_device PCI: print out PCI device info along with duration PCI: Move "pci reassigndev resource alignment" out of quirks.c PCI: Use class for quirk for usb host controller fixup PCI: Use class for quirk for ti816x class fixup PCI: Use class for quirk for intel e100 interrupt fixup ...
2012-03-08PCI: ignore pre-1.1 ASPM quirking when ASPM is disabledMatthew Garrett1-0/+3
Right now we won't touch ASPM state if ASPM is disabled, except in the case where we find a device that appears to be too old to reliably support ASPM. Right now we'll clear it in that case, which is almost certainly the wrong thing to do. The easiest way around this is just to disable the blacklisting when ASPM is disabled. Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-17PCI: pcie: Add support for setting default ASPM policyMatthew Garrett1-0/+8
Distributions may wish to provide different defaults for PCIE ASPM depending on their target audience. Provide a configuration option for choosing the default policy. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-12-05PCI: Rework ASPM disable codeMatthew Garrett1-21/+37
Right now we forcibly clear ASPM state on all devices if the BIOS indicates that the feature isn't supported. Based on the Microsoft presentation "PCI Express In Depth for Windows Vista and Beyond", I'm starting to think that this may be an error. The implication is that unless the platform grants full control via _OSC, Windows will not touch any PCIe features - including ASPM. In that case clearing ASPM state would be an error unless the platform has granted us that control. This patch reworks the ASPM disabling code such that the actual clearing of state is triggered by a successful handoff of PCIe control to the OS. The general ASPM code undergoes some changes in order to ensure that the ability to clear the bits isn't overridden by ASPM having already been disabled. Further, this theoretically now allows for situations where only a subset of PCIe roots hand over control, leaving the others in the BIOS state. It's difficult to know for sure that this is the right thing to do - there's zero public documentation on the interaction between all of these components. But enough vendors enable ASPM on platforms and then set this bit that it seems likely that they're expecting the OS to leave them alone. Measured to save around 5W on an idle Thinkpad X220. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-06-29PCIe ASPM: forcedly -> forciblyMichael Witten1-1/+1
Merriam-Webster tells us that the word exists. However ... * Google suggests `forcibly' because it doesn't recognize `forcedly'. * Google lists 494 thousand results for `forcedly'. * Google lists 13.7 million results for `forcibly'. * Linus's repo contains 1 occurrence of `forcedly' ( 0 after my change). * Linus's repo contains 60 occurrences of `forcibly' (61 after my change). Signed-off-by: Michael Witten <mfwitten@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-21PCI/e1000e: Add and use pci_disable_link_state_locked()Yinghai Lu1-3/+16
Need to use it in _e1000e_disable_aspm. This routine is used for error recovery, where the pci_bus_sem is already held, and we don't want pci_disable_link_state to try to take it again. So add a locked variant for use in cases like this. Found lock up: [ 2374.654557] kworker/32:1 D ffff881027f6b0f0 0 6075 2 0x00000000 [ 2374.654816] ffff88503f099a68 0000000000000046 ffff88503f098000 0000000000004000 [ 2374.654837] 00000000001d1ec0 ffff88503f099fd8 00000000001d1ec0 ffff88503f099fd8 [ 2374.654860] 0000000000004000 00000000001d1ec0 ffff88503dcc8000 ffff88503f090000 [ 2374.654880] Call Trace: [ 2374.654898] [<ffffffff810b1302>] ? __lock_acquired+0x3a/0x224 [ 2374.654914] [<ffffffff81c2b59c>] ? _raw_spin_unlock_irq+0x30/0x36 [ 2374.654925] [<ffffffff810b069d>] ? trace_hardirqs_on_caller+0x1f/0x178 [ 2374.654936] [<ffffffff81c2ab24>] rwsem_down_failed_common+0xd3/0x103 [ 2374.654945] [<ffffffff810b158f>] ? __lock_contended+0x3a/0x2a2 [ 2374.654955] [<ffffffff81c2ab7b>] rwsem_down_read_failed+0x12/0x14 [ 2374.654967] [<ffffffff813371e4>] call_rwsem_down_read_failed+0x14/0x30 [ 2374.654981] [<ffffffff8135df20>] ? pci_disable_link_state+0x5f/0xf5 [ 2374.654990] [<ffffffff81c2a0e6>] ? down_read+0x7e/0x91 [ 2374.654999] [<ffffffff8135df20>] ? pci_disable_link_state+0x5f/0xf5 [ 2374.655008] [<ffffffff8135df20>] pci_disable_link_state+0x5f/0xf5 [ 2374.655024] [<ffffffff81661796>] e1000e_disable_aspm+0x55/0x5a [ 2374.655037] [<ffffffff816677eb>] e1000_io_slot_reset+0x59/0xea [ 2374.655048] [<ffffffff8135fe0d>] ? report_mmio_enabled+0x5d/0x5d [ 2374.655057] [<ffffffff8135fe3b>] report_slot_reset+0x2e/0x5d [ 2374.655072] [<ffffffff8135369e>] pci_walk_bus+0x8a/0xb7 [ 2374.655081] [<ffffffff8135fe0d>] ? report_mmio_enabled+0x5d/0x5d [ 2374.655091] [<ffffffff813603be>] broadcast_error_message+0xa4/0xb2 [ 2374.655101] [<ffffffff81352c71>] ? pci_bus_read_config_dword+0x72/0x80 [ 2374.655110] [<ffffffff813606df>] do_recovery+0x9e/0xf9 [ 2374.655120] [<ffffffff81360786>] handle_error_source+0x4c/0x51 [ 2374.655129] [<ffffffff81360974>] aer_isr_one_error+0x1e9/0x21a [ 2374.655138] [<ffffffff81360a6c>] aer_isr+0xc7/0xcc [ 2374.655147] [<ffffffff813609a5>] ? aer_isr_one_error+0x21a/0x21a [ 2374.655159] [<ffffffff81096d9f>] process_one_work+0x237/0x3ec [ 2374.655168] [<ffffffff81096d10>] ? process_one_work+0x1a8/0x3ec [ 2374.655178] [<ffffffff8109728d>] worker_thread+0x17c/0x240 [ 2374.655186] [<ffffffff810b0803>] ? trace_hardirqs_on+0xd/0xf [ 2374.655196] [<ffffffff81097111>] ? manage_workers+0xab/0xab [ 2374.655209] [<ffffffff8109c8ed>] kthread+0xa0/0xa8 [ 2374.655223] [<ffffffff81c332d4>] kernel_thread_helper+0x4/0x10 [ 2374.655232] [<ffffffff81c2b880>] ? retint_restore_args+0xe/0xe [ 2374.655243] [<ffffffff8109c84d>] ? __init_kthread_worker+0x5b/0x5b [ 2374.655252] [<ffffffff81c332d0>] ? gs_change+0xb/0xb when aer happens, pci_walk_bus already have down_read(&pci_bus_sem)... then report_slot_reset ==> e1000_io_slot_reset ==> e1000e_disable_aspm ==> pci_disable_link_state... We can not use pci_disable_link_state, and it will try to hold pci_bus_sem again. Try to have __pci_disable_link_state that will not need to hold pci_bus_sem. -v2: change name to pci_disable_link_state_locked() according to Jesse. [jbarnes: make sure new function is exported for modules] Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2011-05-11PCI: Enable ASPM state clearing regardless of policyAlex Williamson1-1/+1
Commit 2f671e2d allowed us to clear ASPM state when the FADT tells us it isn't supported, but we don't put this into effect if the aspm_policy is set to POLICY_POWERSAVE. Enable the state to be cleared regardless of policy. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>