diff options
| author | Rafael J. Wysocki <[email protected]> | 2020-12-11 20:17:35 +0000 |
|---|---|---|
| committer | Bjorn Helgaas <[email protected]> | 2020-12-11 23:20:36 +0000 |
| commit | aa0b1574fd36f6929f0a3094342a08622c80b4d1 (patch) | |
| tree | 61f2e19c30b5b7118badd46097cbd652374bbe99 /fs/proc/array.c | |
| parent | PCI: Keep both device and resource name for config space remaps (diff) | |
| download | kernel-aa0b1574fd36f6929f0a3094342a08622c80b4d1.tar.gz kernel-aa0b1574fd36f6929f0a3094342a08622c80b4d1.zip | |
PCI/ACPI: Fix companion lookup for device 0 on the root bus
In some cases acpi_pci_find_companion() returns an incorrect device object
as the ACPI companion for device 0 on the root bus (bus 0).
On the affected systems that device is the PCI interface to the host bridge
and the "ACPI companion" returned for it corresponds to a non-PCI device
located in the SoC (e.g. a sensor on an I2C bus). As a result of this, the
ACPI device object "attached" to PCI device 00:00.0 cannot be used for
enumerating the device that is really represented by it which (of course)
is problematic.
Address that issue by preventing acpi_pci_find_companion() from returning a
device object with a valid _HID (which by the spec should not be present
uder ACPI device objects corresponding to PCI devices) for PCI device
00:00.0.
[bhelgaas: use pci_is_root_bus()]
Link: https://lore.kernel.org/linux-acpi/[email protected]/
Link: https://lore.kernel.org/r/4673285.9aE2nYKHPr@kreacher
Reported-by: Daniel Scally <[email protected]>
Tested-by: Daniel Scally <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Daniel Scally <[email protected]>
Diffstat (limited to 'fs/proc/array.c')
0 files changed, 0 insertions, 0 deletions