dummy/linux-stable-mirror
1
0
Fork 1
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2025-04-19 20:58:31 +09:00
Code Issues Packages Projects Releases Wiki Activity

Revert "PCI: Avoid reset when disabled via sysfs"

Browse Source 
This reverts commit 479380efe1625e251008d24b2810283db60d6fcd.

The reset_method attribute on a PCI device is only intended to manage the
availability of function scoped resets for a device.  It was never intended
to restrict resets targeting the bus or slot.

In introducing a restriction that each device must support function level
reset by testing pci_reset_supported(), we essentially create a catch-22,
that a device must have a function scope reset in order to support bus/slot
reset, when we use bus/slot reset to effect a reset of a device that does
not support a function scoped reset, especially multi-function devices.

This breaks the majority of uses cases where vfio-pci uses bus/slot resets
to manage multifunction devices that do not support function scoped resets.

Fixes: 479380efe162 ("PCI: Avoid reset when disabled via sysfs")
Reported-by: Cal Peake <cp@absolutedigital.net>
Closes: https://lore.kernel.org/all/808e1111-27b7-f35b-6d5c-5b275e73677b@absolutedigital.net
Reported-by: Athul Krishna <athul.krishna.kr@protonmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220010
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250414211828.3530741-1-alex.williamson@redhat.com
This commit is contained in:
Alex Williamson 2025-04-14 15:18:23 -06:00 committed by Bjorn Helgaas
parent 0af2f6be1b
commit bc0b828ef6
1 changed files with 0 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/pci/pci.c
View File

@ -5429,8 +5429,6 @@ static bool pci_bus_resettable(struct pci_bus *bus)
return false;
list_for_each_entry(dev, &bus->devices, bus_list) {
if (!pci_reset_supported(dev))
return false;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
(dev->subordinate && !pci_bus_resettable(dev->subordinate)))
return false;
@ -5507,8 +5505,6 @@ static bool pci_slot_resettable(struct pci_slot *slot)
list_for_each_entry(dev, &slot->bus->devices, bus_list) {
if (!dev->slot || dev->slot != slot)
continue;
if (!pci_reset_supported(dev))
return false;
if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
(dev->subordinate && !pci_bus_resettable(dev->subordinate)))
return false;