Re: [PATCH 2/2] PCI/MSI: Update MSI-X irq domain hwsize

[Guixin Liu <kanie@linux.alibaba.com>]

在 2026/3/25 15:42, Thomas Gleixner 写道:
> On Wed, Mar 25 2026 at 09:34, Guixin Liu wrote:
>> 在 2026/3/24 21:59, Thomas Gleixner 写道:
>>> On Tue, Mar 24 2026 at 09:47, Guixin Liu wrote:
>>>> After the upper-layer driver removes the device and before the next
>>>> probe, events such as firmware updates may increase the number of
>>>> interrupts supported by the device. However, the irq_domain still
>>>> retains the old hwsize, which causes subsequent interrupt allocation
>>>> failures. Update hwsize during MSI-X device domain setup to fix this
>>>> issue.
>>> When a device is removed then the corresponding struct device is torn
>>> down, which implies that the device domain is freed as well. So how can
>>> this end up with the old state on the next probe?
>> Hi, My description was a bit ambiguous. The msi_device_data_release()
>> path to remove the irq_domain is only triggered when the device is
>> removed at the PCI layer. If only the upper-layer driver unbinds,
>> this path will not be reached.
> What's an upper-layer driver? Please be precise.
>
> I assume you are talking about the device driver itself.
Sorry, My description is not very accurate, yes, it's device driver.
> Right, the
> unbind of the driver won't remove the domain. But there is no real good
> reason for keeping it around at that point.
>
> So the straight forward solution is to free the MSI domain when the
> driver shuts down and tears the MSI interrupts down.
Yes, I had also considered this aspect before, I will change the scheme 
to this,
and send another patch, thanks.

Best Regards,
Guixin Liu
>
> Thanks,
>
>          tglx
>