Re: [PATCHv4 3/3] pci: make reset_subordinate hotplug safe

[<dan.j.williams@intel.com>]

Keith Busch wrote:
> From: Keith Busch <kbusch@kernel.org>
> 
> 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.

Did you want to copy that useful error report with the GHES details etc
from http://lore.kernel.org/20260205212533.1512153-4-kbusch@meta.com? I
thought it was useful to clarify this can fix panics.

>   # 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>
[..]
> @@ -5670,6 +5648,58 @@ int pci_try_reset_bus(struct pci_bus *bus)
>  	return rc;
>  }
>  
> +/**
> + * pci_reset_bridge - reset a bridge's subordinate bus
> + * @bridge: bridge that connects to the bus to reset
> + * @restore: true if affected device states need to be restored after the reset

Maybe be more explicit and say:

@restore: when true use a reset method that invokes pci_dev_restore() post reset

...because pci_dev_restore() does a little bit more than just state
restoration.

With or without those minor fixups:

Reviewed-by: Dan Williams <dan.j.williams@intel.com>