Re: [PATCH 1/3] drm/xe/oa/uapi: Expose MERT OA unit

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

On Mon, 08 Dec 2025 11:53:26 -0800, Rodrigo Vivi wrote:
>

Hi Rodrigo,

> On Mon, Dec 08, 2025 at 11:10:13AM -0800, Dixit, Ashutosh wrote:
> > On Mon, 08 Dec 2025 04:48:13 -0800, Rodrigo Vivi wrote:
> > >
> >
> > Hi Rodrigo,
> >
> > > On Fri, Dec 05, 2025 at 01:26:11PM -0800, Ashutosh Dixit wrote:
> > > > A MERT OA unit is available in the SoC on some platforms. Add support
> > > > for this OA unit and expose it to userspace. The MERT OA unit does not
> > > > have any HW engines attached, but is otherwise similar to an OAM unit.
> > > >
> > > > Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> > > > Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
> > > > Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
> > > > diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> > > > index 876a076fa6c0c..f520462c28643 100644
> > > > --- a/include/uapi/drm/xe_drm.h
> > > > +++ b/include/uapi/drm/xe_drm.h
> > > > @@ -1675,6 +1675,9 @@ enum drm_xe_oa_unit_type {
> > > >
> > > >	/** @DRM_XE_OA_UNIT_TYPE_OAM_SAG: OAM_SAG OA unit */
> > > >	DRM_XE_OA_UNIT_TYPE_OAM_SAG,
> > > > +
> > > > +	/** @DRM_XE_OA_UNIT_TYPE_MERT: MERT OA unit */
> > > > +	DRM_XE_OA_UNIT_TYPE_MERT,
> > >
> > > And who&where is the usage here?
> >
> > Sorry I just merged this.
>
> No worries, I just force pushed it out.
>
> > I will provide the MDAPI UMD pull request for
> > this when it is available. Hope this is ok.
>
> Let's re-merge when we see the usage out there.

We now have a MDAPI PR for this feature:

	https://github.com/intel/metrics-discovery/pull/37

I am still waiting for the PR to be reviewed, it is expected to be reviewed
by EOW, at which point I am planning to re-merge this series (after
updating this email thread). MDAPI will merge their PR after the holidays.

Hope this plan is ok.

Thanks.
--
Ashutosh

>
> >
> > This functionality (memory access counters) was part of OAG OA unit but is
> > now separated out into a separate OA unit on some platforms.
>
> Yeap, but any flag or anything that changes the uapi we do in the defined
> order:
>
> 1. both kernel and user space patches are sent out together and reviewed
>    in paralell.
> 2. kernel code is acked by user-space developers (apparently not relevant
>    in this case)
> 3. kernel patch lands first. (Here we have the user-space review already
>    finished and ready to get merged)
> 4. user space patch lands right after.
>
> Thanks,
> Rodrigo.
>
> >
> > Thanks.
> > --
> > Ashutosh