PCI/sysfs: Ensure devices are powered for config reads

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commit 48991e4935 upstream.

The "max_link_width", "current_link_speed", "current_link_width",
"secondary_bus_number", and "subordinate_bus_number" sysfs files all access
config registers, but they don't check the runtime PM state. If the device
is in D3cold or a parent bridge is suspended, we may see -EINVAL, bogus
values, or worse, depending on implementation details.

Wrap these access in pci_config_pm_runtime_{get,put}() like most of the
rest of the similar sysfs attributes.

Notably, "max_link_speed" does not access config registers; it returns a
cached value since d2bd39c045 ("PCI: Store all PCIe Supported Link
Speeds").

Fixes: 56c1af4606 ("PCI: Add sysfs max_link_speed/width, current_link_speed/width, etc")
Signed-off-by: Brian Norris <briannorris@google.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250924095711.v2.1.Ibb5b6ca1e2c059e04ec53140cd98a44f2684c668@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Brian Norris 2025-09-24 09:57:11 -07:00 • committed by Greg Kroah-Hartman

parent 3d01eb9f5a

commit f16ab42cc2

1 changed files with 19 additions and 1 deletions

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drivers/pci/pci-sysfs.c

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