Re: [PATCH] drm/i915/selftests: Set always_coherent to false when reading from CPU

[Jani Nikula <jani.nikula@linux.intel.com>]

On Thu, 16 May 2024, Nirmoy Das <nirmoy.das@intel.com> wrote:
> The previous commit 'commit 8d4ba9fc1c6c ("drm/i915/selftests: Pick

"previous commit" is a fairly vague reference once this gets
committed. It's not going to be "previous" in any meaningful sense.

Please just start with:

Commit 8d4ba9fc1c6c ("drm/i915/selftests: Pick correct caching mode.")
was not complete...

And probably add:

Fixes: 8d4ba9fc1c6c ("drm/i915/selftests: Pick correct caching mode.")

BR,
Jani.

> correct caching mode.")' was not complete as for non LLC  sharing platforms
> cpu read can happen from LLC which probably doesn't have the latest
> changes made by GPU.
>
> Cc: Andi Shyti <andi.shyti@linux.intel.com>
> Cc: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
> Cc: Jonathan Cavitt <jonathan.cavitt@intel.com>
> Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
> ---
>  drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
> index 65a931ea80e9..3527b8f446fe 100644
> --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
> +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
> @@ -196,7 +196,7 @@ static int verify_access(struct drm_i915_private *i915,
>  	if (err)
>  		goto out_file;
>  
> -	mode = intel_gt_coherent_map_type(to_gt(i915), native_obj, true);
> +	mode = intel_gt_coherent_map_type(to_gt(i915), native_obj, false);
>  	vaddr = i915_gem_object_pin_map_unlocked(native_obj, mode);
>  	if (IS_ERR(vaddr)) {
>  		err = PTR_ERR(vaddr);

-- 
Jani Nikula, Intel