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| author | Alexandru Gagniuc <mr.nuke.me@gmail.com> | 2020-04-28 02:25:13 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2020-05-01 01:19:12 +0300 |
| commit | c100beb9ccfb98e2474586a4006483cbf770c823 (patch) | |
| tree | 68b9a4db318946290607bfe36ba3e6c7c234d7a5 /drivers/acpi/pci_root.c | |
| parent | af03958da0678c3162ae534829cabf9f67f0d950 (diff) | |
| download | linux-c100beb9ccfb98e2474586a4006483cbf770c823.tar.xz | |
PCI/AER: Use only _OSC to determine AER ownership
Per the PCI Firmware spec, r3.2, sec 4.5.1, the OS can request control of
AER via bit 3 of the _OSC Control Field. In the returned value of the
Control Field:
The firmware sets [bit 3] to 1 to grant control over PCI Express Advanced
Error Reporting. ... after control is transferred to the operating
system, firmware must not modify the Advanced Error Reporting Capability.
If control of this feature was requested and denied or was not requested,
firmware returns this bit set to 0.
Previously the pci_root driver looked at the HEST FIRMWARE_FIRST bit to
determine whether to request ownership of the AER Capability. This was
based on ACPI spec v6.3, sec 18.3.2.4, and similar sections, which say
things like:
Bit [0] - FIRMWARE_FIRST: If set, indicates that system firmware will
handle errors from this source first.
Bit [1] - GLOBAL: If set, indicates that the settings contained in this
structure apply globally to all PCI Express Devices.
These ACPI references don't say anything about ownership of the AER
Capability.
Remove use of the FIRMWARE_FIRST bit and rely only on the _OSC bit to
determine whether we have control of the AER Capability.
Link: https://lore.kernel.org/r/20181115231605.24352-1-mr.nuke.me@gmail.com/ v1
Link: https://lore.kernel.org/r/20190326172343.28946-1-mr.nuke.me@gmail.com/ v2
Link: https://lore.kernel.org/r/67af2931705bed9a588b5a39d369cb70b9942190.1587925636.git.sathyanarayanan.kuppuswamy@linux.intel.com
[bhelgaas: commit log, note: Alex posted this identical patch 18 months
ago, and I failed to apply it then, so I made him the author, added links
to his postings, and added his Signed-off-by]
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Diffstat (limited to 'drivers/acpi/pci_root.c')
| -rw-r--r-- | drivers/acpi/pci_root.c | 9 |
1 files changed, 2 insertions, 7 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index ac8ad6cb82aa..9e235c1a75ff 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -483,13 +483,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm, if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC)) control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL; - if (pci_aer_available()) { - if (aer_acpi_firmware_first()) - dev_info(&device->dev, - "PCIe AER handled by firmware\n"); - else - control |= OSC_PCI_EXPRESS_AER_CONTROL; - } + if (pci_aer_available()) + control |= OSC_PCI_EXPRESS_AER_CONTROL; /* * Per the Downstream Port Containment Related Enhancements ECN to |