Re: [PATCH V5 3/3] PCI: Mask and unmask hotplug interrupts during reset

From: poza
Date: Wed Jul 25 2018 - 04:29:22 EST


On 2018-07-21 11:37, Sinan Kaya wrote:
On 7/20/2018 7:58 PM, Sinan Kaya wrote:
We need to figure out how to gracefully return inside hotplug driver
if link down happened and there is an error pending.

How about adding the following into the hotplug ISR?

1. check if firmware first is disabled
2. check if there is a fatal error pending in the device_status register
of the PCI Express capability on the root port.
3. bail out from hotplug routine if this is the case.
4. otherwise, existing behavior.

This makes sense.

from Lukas's text

"
The user may turn the slot on/off via sysfs. If an Attention Button
is present, the user may also press that button to turn the slot on/off
after 5 seconds. Either way, it may cause pciehp's IRQ thread to run
concurrently to a reset initiated by the AER driver, independently of
any events signalled by the slot.
"

so if device gets removed and re-enumerated other than hotplug ISR,
or any other similar path has to take care of checking ERR_FATAL status.

Regards,
Oza.