linux/drivers/pci
Alex Williamson 41044d5360 PCI: Fix active state requirement in PME polling
The commit noted in fixes added a bogus requirement that runtime PM managed
devices need to be in the RPM_ACTIVE state for PME polling.  In fact, only
devices in low power states should be polled.

However there's still a requirement that the device config space must be
accessible, which has implications for both the current state of the polled
device and the parent bridge, when present.  It's not sufficient to assume
the bridge remains in D0 and cases have been observed where the bridge
passes the D0 test, but the PM state indicates RPM_SUSPENDING and config
space of the polled device becomes inaccessible during pci_pme_wakeup().

Therefore, since the bridge is already effectively required to be in the
RPM_ACTIVE state, formalize this in the code and elevate the PM usage count
to maintain the state while polling the subordinate device.

This resolves a regression reported in the bugzilla below where a
Thunderbolt/USB4 hierarchy fails to scan for an attached NVMe endpoint
downstream of a bridge in a D3hot power state.

Link: https://lore.kernel.org/r/20240123185548.1040096-1-alex.williamson@redhat.com
Fixes: d3fcd73603 ("PCI: Fix runtime PM race with PME polling")
Reported-by: Sanath S <sanath.s@amd.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218360
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Sanath S <sanath.s@amd.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
2024-02-09 13:03:21 -06:00
..
controller pci-v6.8-changes 2024-01-17 16:23:17 -08:00
endpoint Char/Misc and other Driver changes for 6.8-rc1 2024-01-17 16:47:17 -08:00
hotplug Revert "PCI: acpiphp: Reassign resources on bridge if necessary" 2023-12-15 14:55:10 -06:00
msi PCI/MSI: Use FIELD_GET/PREP() 2023-10-24 10:54:04 -05:00
pcie pci-v6.8-changes 2024-01-17 16:23:17 -08:00
switch PCI: switchtec: Fix stdev_release() crash after surprise hot remove 2023-11-22 09:44:06 -06:00
access.c PCI: Move pci_clear_and_set_dword() helper to PCI header 2023-12-13 13:35:41 +00:00
ats.c PCI/ATS: Use FIELD_GET() 2023-10-24 16:55:45 -05:00
bus.c Devicetree updates for v6.6: 2023-08-30 16:59:03 -07:00
doe.c PCI/DOE: Fix destroy_work_on_stack() race 2023-07-27 15:20:47 -05:00
ecam.c
host-bridge.c
iov.c PCI: Use resource names in PCI log messages 2023-12-15 17:28:42 -06:00
irq.c
Kconfig PCI: Replace unnecessary UTF-8 in Kconfig 2023-10-06 14:30:48 -05:00
Makefile PCI: Create device tree node for bridge 2023-08-22 14:56:09 -05:00
mmap.c
of_property.c PCI: of_property: Handle interrupt parsing failures 2023-09-29 17:33:46 -05:00
of.c PCI: of: Destroy changeset when adding PCI device node fails 2023-09-29 17:33:51 -05:00
p2pdma.c PCI/P2PDMA: Remove redundant goto 2023-10-23 12:17:52 -05:00
pci-acpi.c Merge branch 'pci/pm' 2023-10-28 13:30:59 -05:00
pci-bridge-emul.c
pci-bridge-emul.h
pci-driver.c PCI/PM: Mark devices disconnected if upstream PCIe link is down on resume 2023-09-29 17:42:00 -05:00
pci-label.c
pci-mid.c
pci-pf-stub.c
pci-stub.c
pci-sysfs.c Driver core changes for 6.7-rc1 2023-11-03 15:15:47 -10:00
pci.c PCI: Fix active state requirement in PME polling 2024-02-09 13:03:21 -06:00
pci.h pci-v6.8-changes 2024-01-17 16:23:17 -08:00
probe.c PCI: Log bridge info when first enumerating bridge 2023-12-15 17:28:43 -06:00
proc.c
quirks.c pci-v6.8-changes 2024-01-17 16:23:17 -08:00
remove.c PCI: Create device tree node for bridge 2023-08-22 14:56:09 -05:00
rom.c
search.c PCI: Add pci_get_base_class() helper 2023-09-28 16:49:44 -05:00
setup-bus.c PCI: Use resource names in PCI log messages 2023-12-15 17:28:42 -06:00
setup-irq.c
setup-res.c PCI: Use resource names in PCI log messages 2023-12-15 17:28:42 -06:00
slot.c
syscall.c PCI: Use consistent put_user() pointer types 2023-08-25 08:15:13 -05:00
vc.c PCI/VC: Use FIELD_GET() 2023-10-24 16:55:45 -05:00
vgaarb.c pci-v6.7-changes 2023-11-02 14:05:18 -10:00
vpd.c PCI/VPD: Add runtime power management to sysfs interface 2023-08-11 14:19:16 -05:00
xen-pcifront.c x86: always initialize xen-swiotlb when xen-pcifront is enabling 2023-07-31 17:54:27 +02:00