[PATCH] drm/amdgpu: Fix Manual Execution of Cleaner Shader in Gang Submissions

[Alex Deucher]

On Thu, Mar 27, 2025 at 5:37 AM SRINIVASAN SHANMUGAM
<srinivasan.shanmugam at amd.com> wrote:
>
>
> On 3/27/2025 2:54 PM, Christian König wrote:
>
>
> Over all this change doesn't seem to make much sense to me.
>
> Why exactly is isolation->spearhead not pointing to the dummy kernel job we submit?
>
> Does the owner check or gang_submit check in
> amdgpu_device_enforce_isolation() fail to set up the spearhead?
>
> I'm currently debugging exactly that.
>
> Good news is that I can reproduce the problem.
>
>
> I have to take that back. I've tested the cleaner shader functionality a bit this morning and as far as I can see this works exactly as intended.
>
> Srini, what exactly is your use case which doesn't work?
>
> Hi Christian, Good Morning!
>
> The usecase is to trigger the cleaner shader, using sysfs "run_cleaner_shader" independent of  enabling "enforce_isolation", so that cleaner shader packet gets submitted to COMP_1.0.0 ring by default, without prior enabling any enforce_isolation via sysfs,

Right.  We want to be able to manually run the cleaner shader via
sysfs regardless of whether runtime enforce isolation is enabled or
not.

Alex

>
> AFAIK, this "isolation->spearhead" initialization is not being takencare in this path "amdgpu_gfx_run_cleaner_shader -> amdgpu_gfx_run_cleaner_shader_job" (ie., when we trigger cleaner shader, using sysfs "run_cleaner_shader"), and this check "&job->base.s_fence->scheduled == isolation->spearhead;"  is having the problem ie., "&job->base.s_fence->scheduled" address are is not matching with "isolation->spearhead" address, which results into zero & thus fails to emit cleaner shader, when running using "run_cleaner_shader" sysfs entry, in "amdgpu_vm_flush()" function
>
> Best regards,
>
> Srini
>
>
> Regards,
> Christian.
>
> Regards,
> Christian.