Re: [PATCH 2/2] drm/xe/hwmon: Increase timeout for mailbox power limits

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Aug 31, 2026 at 09:57:26PM +0530, Poosa, Karthik wrote:
> 
> On 31-08-2026 19:28, Rodrigo Vivi wrote:
> > On Mon, Aug 31, 2026 at 09:41:45AM +0200, Raag Jadav wrote:
> > > On Mon, Aug 31, 2026 at 12:39:50PM +0530, Tauro, Riana wrote:
> > > > On 31-08-2026 12:24, Poosa, Karthik wrote:
> > > > > On 31-08-2026 10:59, Tauro, Riana wrote:
> > > > > > On 29-07-2026 22:45, Karthik Poosa wrote:
> > > > > > > Mailbox power limit operations can occasionally take longer than the
> > > > > > > current 1 ms timeout, causing sporadic failures.
> > > Why?
> > > 
> > > > > > > Increase the timeout to 10 ms and rename PL_WRITE_MBX_TIMEOUT_MS to
> > > > > > > PL_MBX_TIMEOUT_MS to better reflect its usage.
> > > > > > Why is the timeout applicable only for power and not the other
> > > > > > attribute reads?
> > > > > Because the timeout is seen only with mailbox power limit commands only,
> > > > > default 1ms timeout wasn't enough here.
> > > > Any reason why this is not seen for the other reads?
> > > +1, these things should be coming from a hard spec with valid technical
> > > justification and not some random email asking us to do so.
> > Well, you have such high expectations :)
> > Sometimes we have to live with the empirical... while we hunt other teams asking
> > them to do their job correctly, of course...
> > 
> > Interestingly enough, I just found in some of the many spread pcode docs:
> > 
> > driver_to_pcode_mailbox_spec.html#mailbox-response-time
> > 
> > """
> > Mailbox response time
> > Mailbox response timeout shoudl be set to 10ms as worst case.
> > """
> > 
> > Perhaps we should simply change the default to 10ms.
> 
> Investigation is ongoing to understand why some pcode mailbox commands
> occasionally take longer to complete.
> 
> Until then, using the documented worst-case timeout as default timeout seems
> the better approach.

I agree.

Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
in advance...

> 
> > 
> > > Raag