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Date:   Wed, 25 Jul 2018 13:59:16 +0530
From:   poza@codeaurora.org
To:     Sinan Kaya <okaya@kernel.org>
Cc:     Bjorn Helgaas <helgaas@kernel.org>, Lukas Wunner <lukas@wunner.de>,
        linux-pci@vger.kernel.org,
        open list <linux-kernel@vger.kernel.org>,
        Keith Busch <keith.busch@intel.com>,
        linux-arm-msm@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
        linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH V5 3/3] PCI: Mask and unmask hotplug interrupts during
 reset
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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.