2023-09-13 00:32:41

by Smita Koralahalli

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] PCI: pciehp: Add support for async hotplug with native AER and DPC/EDR

On 8/28/2023 12:35 AM, Lukas Wunner wrote:
> On Tue, Aug 15, 2023 at 09:20:41PM +0000, Smita Koralahalli wrote:
>> According to PCIe r6.0 sec 6.7.6 [1], async removal with DPC may result in
>> surprise down error. This error is expected and is just a side-effect of
>> async remove.
>>
>> Add support to handle the surprise down error generated as a side-effect
>> of async remove. Typically, this error is benign as the pciehp handler
>> invoked by PDC or/and DLLSC alongside DPC, de-enumerates and brings down
>> the device appropriately. But the error messages might confuse users. Get
>> rid of these irritating log messages with a 1s delay while pciehp waits
>> for dpc recovery.
> [...]
>> Signed-off-by: Smita Koralahalli <[email protected]>
>
> Reviewed-by: Lukas Wunner <[email protected]>
>
> The subject is slightly inaccurate as this doesn't touch pciehp source
> files, although it is *related* to pciehp.
>
> As an example, a perhaps more accurate subject might be something like...
>
> PCI/DPC: Ignore Surprise Down errors on hot removal
>
> ...but I don't think it's necessary to respin just for that as Bjorn is
> probably able to adjust the subject to his liking when applying the patch.
>
> Thanks a lot for patiently pursuing this issue, good to see it fixed.
>
> Five years ago there was an attempt to solve it through masking Surprise
> Down errors, which you've verified to not be a viable approach:
>
> https://patchwork.kernel.org/project/linux-pci/patch/[email protected]/
>
> Lukas

Thanks for the review. Would it be possible to consider this patch as a
standalone while I work on 10-bit tags enumeration? I can do v5 for this
patch with $SUBJECT changes and also include clearing Atomic Ops and
10-bit tags unconditionally on hot-remove if that works..

Thanks,
Smita


2023-09-13 04:08:09

by Lukas Wunner

[permalink] [raw]
Subject: Re: [PATCH v4 1/3] PCI: pciehp: Add support for async hotplug with native AER and DPC/EDR

On Tue, Sep 12, 2023 at 03:45:34PM -0700, Smita Koralahalli wrote:
> Thanks for the review. Would it be possible to consider this patch as a
> standalone while I work on 10-bit tags enumeration? I can do v5 for this
> patch with $SUBJECT changes and also include clearing Atomic Ops and 10-bit
> tags unconditionally on hot-remove if that works..

Right, this patch is still in state "New" in patchwork:

https://patchwork.kernel.org/project/linux-pci/patch/[email protected]/

Which means Bjorn probably hasn't gotten a chance to look at it.
Indeed it can be applied standalone if Bjorn gets to it this cycle
and doesn't have any objections.

Feel free to include my Reviewed-by tag if/when resending.

Thanks,

Lukas