BMC/Intel-BMC/linux.git/drivers/base, branch dev-5.14-intel

driver core: fw_devlink: Improve handling of cyclic dependencies

2021-10-07T05:53:17+00:00

commit 2de9d8e0d2fe3a1eb632def2245529067cb35db5 upstream. When we have a dependency of the form: Device-A -> Device-C Device-B Device-C -> Device-B Where, * Indentation denotes "child of" parent in previous line. * X -> Y denotes X is consumer of Y based on firmware (Eg: DT). We have cyclic dependency: device-A -> device-C -> device-B -> device-A fw_devlink current treats device-C -> device-B dependency as an invalid dependency and doesn't enforce it but leaves the rest of the dependencies as is. While the current behavior is necessary, it is not sufficient if the false dependency in this example is actually device-A -> device-C. When this is the case, device-C will correctly probe defer waiting for device-B to be added, but device-A will be incorrectly probe deferred by fw_devlink waiting on device-C to probe successfully. Due to this, none of the devices in the cycle will end up probing. To fix this, we need to go relax all the dependencies in the cycle like we already do in the other instances where fw_devlink detects cycles. A real world example of this was reported[1] and analyzed[2]. [1] - https://lore.kernel.org/lkml/0a2c4106-7f48-2bb5-048e-8c001a7c3fda@samsung.com/ [2] - https://lore.kernel.org/lkml/CAGETcx8peaew90SWiux=TyvuGgvTQOmO4BFALz7aj0Za5QdNFQ@mail.gmail.com/ Fixes: f9aa460672c9 ("driver core: Refactor fw_devlink feature") Cc: stable Reported-by: Marek Szyprowski Tested-by: Marek Szyprowski Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210915170940.617415-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

driver core: fw_devlink: Add support for FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD

2021-10-07T05:53:11+00:00

[ Upstream commit 5501765a02a6c324f78581e6bb8209d054fe13ae ] If a parent device is also a supplier to a child device, fw_devlink=on by design delays the probe() of the child device until the probe() of the parent finishes successfully. However, some drivers of such parent devices (where parent is also a supplier) expect the child device to finish probing successfully as soon as they are added using device_add() and before the probe() of the parent device has completed successfully. One example of such a case is discussed in the link mentioned below. Add a flag to make fw_devlink=on not enforce these supplier-consumer relationships, so these drivers can continue working. Link: https://lore.kernel.org/netdev/CAGETcx_uj0V4DChME-gy5HGKTYnxLBX=TH2rag29f_p=UcG+Tg@mail.gmail.com/ Fixes: ea718c699055 ("Revert "Revert "driver core: Set fw_devlink=on by default""") Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20210915170940.617415-3-saravanak@google.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

software node: balance refcount for managed software nodes

2021-09-30T08:13:07+00:00

commit 5aeb05b27f81269a2bf2e15eab9fc0f9a400d3a8 upstream. software_node_notify(), on KOBJ_REMOVE drops the refcount twice on managed software nodes, thus leading to underflow errors. Balance the refcount by bumping it in the device_create_managed_software_node() function. The error [1] was encountered after adding a .shutdown() op to our fsl-mc-bus driver. [1] pc : refcount_warn_saturate+0xf8/0x150 lr : refcount_warn_saturate+0xf8/0x150 sp : ffff80001009b920 x29: ffff80001009b920 x28: ffff1a2420318000 x27: 0000000000000000 x26: ffffccac15e7a038 x25: 0000000000000008 x24: ffffccac168e0030 x23: ffff1a2428a82000 x22: 0000000000080000 x21: ffff1a24287b5000 x20: 0000000000000001 x19: ffff1a24261f4400 x18: ffffffffffffffff x17: 6f72645f726f7272 x16: 0000000000000000 x15: ffff80009009b607 x14: 0000000000000000 x13: ffffccac16602670 x12: 0000000000000a17 x11: 000000000000035d x10: ffffccac16602670 x9 : ffffccac16602670 x8 : 00000000ffffefff x7 : ffffccac1665a670 x6 : ffffccac1665a670 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000ffffffff x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff1a2420318000 Call trace: refcount_warn_saturate+0xf8/0x150 kobject_put+0x10c/0x120 software_node_notify+0xd8/0x140 device_platform_notify+0x4c/0xb4 device_del+0x188/0x424 fsl_mc_device_remove+0x2c/0x4c rebofind sp.c__fsl_mc_device_remove+0x14/0x2c device_for_each_child+0x5c/0xac dprc_remove+0x9c/0xc0 fsl_mc_driver_remove+0x28/0x64 __device_release_driver+0x188/0x22c device_release_driver+0x30/0x50 bus_remove_device+0x128/0x134 device_del+0x16c/0x424 fsl_mc_bus_remove+0x8c/0x114 fsl_mc_bus_shutdown+0x14/0x20 platform_shutdown+0x28/0x40 device_shutdown+0x15c/0x330 __do_sys_reboot+0x218/0x2a0 __arm64_sys_reboot+0x28/0x34 invoke_syscall+0x48/0x114 el0_svc_common+0x40/0xdc do_el0_svc+0x2c/0x94 el0_svc+0x2c/0x54 el0t_64_sync_handler+0xa8/0x12c el0t_64_sync+0x198/0x19c ---[ end trace 32eb1c71c7d86821 ]--- Fixes: 151f6ff78cdf ("software node: Provide replacement for device_add_properties()") Reported-by: Jon Nettleton Suggested-by: Heikki Krogerus Reviewed-by: Heikki Krogerus Signed-off-by: Laurentiu Tudor Cc: 5.12+ # 5.12+ [ rjw: Fix up the software_node_notify() invocation ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: sleep: core: Avoid setting power.must_resume to false

2021-09-26T12:10:17+00:00

commit 4a9344cd0aa4499beb3772bbecb40bb78888c0e1 upstream. There are variables(power.may_skip_resume and dev->power.must_resume) and DPM_FLAG_MAY_SKIP_RESUME flags to control the resume of devices after a system wide suspend transition. Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver allows its "noirq" and "early" resume callbacks to be skipped if the device can be left in suspend after a system-wide transition into the working state. PM core determines that the driver's "noirq" and "early" resume callbacks should be skipped or not with dev_pm_skip_resume() function by checking power.may_skip_resume variable. power.must_resume variable is getting set to false in __device_suspend() function without checking device's DPM_FLAG_MAY_SKIP_RESUME settings. In problematic scenario, where all the devices in the suspend_late stage are successful and some device can fail to suspend in suspend_noirq phase. So some devices successfully suspended in suspend_late stage are not getting chance to execute __device_suspend_noirq() to set dev->power.must_resume variable to true and not getting resumed in early_resume phase. Add a check for device's DPM_FLAG_MAY_SKIP_RESUME flag before setting power.must_resume variable in __device_suspend function. Fixes: 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase") Signed-off-by: Prasad Sodagudi Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: base: power: don't try to use non-existing RTC for storing data

2021-09-22T10:39:15+00:00

commit 0560204b360a332c321124dbc5cdfd3364533a74 upstream. If there is no legacy RTC device, don't try to use it for storing trace data across suspend/resume. Cc: Signed-off-by: Juergen Gross Reviewed-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/20210903084937.19392-2-jgross@suse.com Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

scsi: ufshcd: Fix device links when BOOT WLUN fails to probe

2021-09-18T11:43:30+00:00

[ Upstream commit bf25967ac54129ffb676ee0dbe3b8b34af6c6232 ] Managed device links are deleted by device_del(). However it is possible to add a device link to a consumer before device_add(), and then discovering an error prevents the device from being used. In that case normally references to the device would be dropped and the device would be deleted. However the device link holds a reference to the device, so the device link and device remain indefinitely (unless the supplier is deleted). For UFSHCD, if a LUN fails to probe (e.g. absent BOOT WLUN), the device will not have been registered but can still have a device link holding a reference to the device. The unwanted device link will prevent runtime suspend indefinitely. Amend device link removal to accept removal of a link with an unregistered consumer device (suggested by Rafael), and fix UFSHCD by explicitly deleting the device link when SCSI destroys the SCSI device. Link: https://lore.kernel.org/r/a1c9bac8-b560-b662-f0aa-58c7e000cbbd@intel.com Fixes: b294ff3e3449 ("scsi: ufs: core: Enable power management for wlun") Reviewed-by: Rafael J. Wysocki Signed-off-by: Adrian Hunter Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

driver core: Fix error return code in really_probe()

2021-09-15T08:02:12+00:00

[ Upstream commit f04948dea236b000da09c466a7ec931ecd8d7867 ] In the case of error handling, the error code returned by the subfunction should be propagated instead of 0. Fixes: 1901fb2604fb ("Driver core: fix "driver" symlink timing") Fixes: 23b6904442d0 ("driver core: add dev_groups to all drivers") Fixes: 8fd456ec0cf0 ("driver core: Add state_synced sysfs file for devices that support it") Reported-by: Hulk Robot Signed-off-by: Zhen Lei Link: https://lore.kernel.org/r/20210707074301.2722-1-thunder.leizhen@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

firmware: fix theoretical UAF race with firmware cache and resume

2021-09-15T08:02:12+00:00

[ Upstream commit 3ecc8cb7c092b2f50e21d2aaaae35b8221ee7214 ] This race was discovered when I carefully analyzed the code to locate another firmware-related UAF issue. It can be triggered only when the firmware load operation is executed during suspend. This possibility is almost impossible because there are few firmware load and suspend actions in the actual environment. CPU0 CPU1 __device_uncache_fw_images(): assign_fw(): fw_cache_piggyback_on_request() <----- P0 spin_lock(&fwc->name_lock); ... list_del(&fce->list); spin_unlock(&fwc->name_lock); uncache_firmware(fce->name); <----- P1 kref_get(&fw_priv->ref); If CPU1 is interrupted at position P0, the new 'fce' has been added to the list fwc->fw_names by the fw_cache_piggyback_on_request(). In this case, CPU0 executes __device_uncache_fw_images() and will be able to see it when it traverses list fwc->fw_names. Before CPU1 executes kref_get() at P1, if CPU0 further executes uncache_firmware(), the count of fw_priv->ref may decrease to 0, causing fw_priv to be released in advance. Move kref_get() to the lock protection range of fwc->name_lock to fix it. Fixes: ac39b3ea73aa ("firmware loader: let caching firmware piggyback on loading firmware") Acked-by: Luis Chamberlain Signed-off-by: Zhen Lei Link: https://lore.kernel.org/r/20210719064531.3733-2-thunder.leizhen@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

regmap: fix the offset of register error log

2021-09-15T08:02:02+00:00

[ Upstream commit 1852f5ed358147095297a09cc3c6f160208a676d ] This patch fixes the offset of register error log by using regmap_get_offset(). Signed-off-by: Jeongtae Park Link: https://lore.kernel.org/r/20210701142630.44936-1-jeongtae.park@gmail.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

PM: domains: Improve runtime PM performance state handling

2021-08-25T18:15:54+00:00

GENPD core doesn't support handling performance state changes while consumer device is runtime-suspended or when runtime PM is disabled. GENPD core may override performance state that was configured by device driver while RPM of the device was disabled or device was RPM-suspended. Let's close that gap by allowing drivers to control performance state while RPM of a consumer device is disabled and to set up performance state of RPM-suspended device that will be applied by GENPD core on RPM-resume of the device. Fixes: 5937c3ce2122 ("PM: domains: Drop/restore performance state votes for devices at runtime PM") Signed-off-by: Dmitry Osipenko Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki