• Rafael J. Wysocki's avatar
    PCI/PCIe/AER: Disable native AER service if BIOS has precedence · b22c3d82
    Rafael J. Wysocki authored
    There is a design issue related to PCIe AER and _OSC that the BIOS
    may be asked to grant control of the AER service even if some
    Hardware Error Source Table (HEST) entries contain information
    meaning that the BIOS really should control it.  Namely,
    pcie_port_acpi_setup() calls pcie_aer_get_firmware_first() that
    determines whether or not the AER service should be controlled by
    the BIOS on the basis of the HEST information for the given PCIe
    port.  The BIOS is asked to grant control of the AER service for
    a PCIe Root Complex if pcie_aer_get_firmware_first() returns 'false'
    for at least one root port in that complex, even if all of the other
    root ports' HEST entries have the FIRMWARE_FIRST flag set (and none
    of them has the GLOBAL flag set).  However, if the AER service is
    controlled by the kernel, that may interfere with the BIOS' handling
    of the error sources having the FIRMWARE_FIRST flag.  Moreover,
    there may be PCIe endpoints that have the FIRMWARE_FIRST flag set in
    HEST and are attached to the root ports in question, in which case it
    also may be unsafe to ask the BIOS for control of the AER service.
    
    For this reason, introduce a function checking if there's at least
    one PCIe-related HEST entry with the FIRMWARE_FIRST flag set and
    disable the native AER service altogether if this function returns
    'true'.
    Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
    Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
    b22c3d82
aerdrv.c 11.9 KB