Re: [PATCH] iommu/amd: Enhance "Completion-wait Time-out" error message

[Dheeraj Kumar Srivastava]

Hi Joerg and Vasant,

On 10/29/2025 4:18 PM, Vasant Hegde wrote:
> On 10/29/2025 2:00 PM, Jörg Rödel wrote:
> > On Tue, Oct 28, 2025 at 02:45:16PM +0530, Vasant Hegde wrote:
> > > We have debugfs support to extract entire command buffer. Also many cases once
> > > we hit completion wait timeout, buffer won't progress.. and we will hit
> > > completion wait repetitively. Hence in V2 he has removed printing entire command
> > > buffer.
> > >
> > > Do you want to log entire buffer once to dmesg if amd_iommu_dump=1 ? (for first
> > > completion wait timeout event).
> >
> > I think there is some value in printing the command buffer contents at the
> > point in time when the timeout happens. When it is read later from debug-fs,
> > the state of the command buffer might already be different, making debugging
> > harder.
>
> Ack. if amd_iommu_dump=1 then we can log entire command buffer to dmesg once.

Sure. I’ll send an updated version for review.

Thanks
Dheeraj

> -Vasant