Re: [PATCH 11/17] drm/xe/oa: Disable overrun mode for Xe2+ OAG

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Tue, 19 Dec 2023 19:05:56 -0800, Umesh Nerlige Ramappa wrote:
>

Hi Umesh,

> On Thu, Dec 07, 2023 at 10:43:23PM -0800, Ashutosh Dixit wrote:
> > Xe2+ OAG requires special handling because non-power-of-2 report sizes are
> > not a sub-multiple of the OA buffer size and there are no partial reports
> > at the end of the buffer. This issue is present only when overrun mode is
> > enabled. Avoid adding this special handling by disabling overrun mode for
> > Xe2+ OAG.
>
> Like you mentioned earlier, maybe disable overrun for all platforms OR have
> the user control the setting.

This patch is mostly a workaround till Xe handles this new thing in HW. But
yes, we should see if it is possible to disable overrun mode altogether.

I was actually saying have overrun mode always enabled and skip the HEAD
pointer update (if we don't expose the read() interface). Anyway let's
discuss some more about this. I will also check with UMD's.

> Otherwise, this is
>
> Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>

Thanks.
--
Ashutosh