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

[Guixin Liu]

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