PCI: Make reset_subordinate hotplug safe

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Use the slot reset method when resetting the bridge if the bus contains
hot plug slots. This fixes spurious hot plug events that are triggered
by the secondary bus reset that bypasses the slot's detection disabling.

Resetting a bridge's subordinate bus can be done like this:

  # echo 1 > /sys/bus/pci/devices/0000:50:01.0/reset_subordinate

Prior to this patch, an example kernel message may show something like:

  pcieport 0000:50:01.0: pciehp: Slot(40): Link Down

With this change, the pciehp driver ignores the link event during the
reset, so may show this message instead:

  pcieport 0000:50:01.0: pciehp: Slot(40): Link Down/Up ignored

Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20260217160836.2709885-4-kbusch@meta.com

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This commit is contained in:

Keith Busch 2026-02-17 08:08:36 -08:00 • committed by Bjorn Helgaas

parent 102c8b26b5

commit 8238cb69c0

3 changed files with 62 additions and 34 deletions

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3

drivers/pci/pci-sysfs.c

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125

drivers/pci/pci.c

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2

drivers/pci/pci.h

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