Re: [PATCH v2 1/1] PCI/hotplug: Add 'uevent' sysfs attribute to trigger slot events

[Niklas Schnelle]

On Thu, 2026-04-16 at 16:39 -0500, Ramesh Errabolu wrote:
> Add a write-only 'uevent' sysfs attribute for synthesizing
> uevents for a PCI slot. This extends the existing uevent
> support which emits a KOBJ_ADD uevent in pci_hp_add() with
> the ability to replay such uevents for cold plugged devices.
> As such events are only emitted by hotplug capable PCI slots
> so is the support for synthesizing them.
> 
> The change was validated by manually triggering 'add' uevent
> for a specific hotplug PCI slot:
> 
>     $ echo "add $(uuidgen)" | sudo tee   \
>                 /sys/bus/pci/slots/<slot-id>/uevent
> 
> Signed-off-by: Ramesh Errabolu <ramesh@xxxxxxxxxxxxx>
> ---
>  drivers/pci/hotplug/pci_hotplug_core.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 

Sorry for the review delay. This looks good to me and will really help
with udev rule execution for devices which are discovered in standby
state during boot and thus currently don't create any uevents. Of
course to work by default this still requires a systemd/udev addition
that I know you're also working on. 

Consequently, I tested the uevent synthesization with both slots with a
configured (slot powered on) and standby (slot powered off) PCI
function.

Feel free to add:

Reviewed-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Tested-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>

Thanks,
Niklas