[Intel-gfx] [PATCH RESEND] drm/i915: Fix display problems after resume

[Andrzej Hajda]

On 05.10.2022 14:11, Thomas Hellström wrote:
> Commit 39a2bd34c933 ("drm/i915: Use the vma resource as argument for gtt
> binding / unbinding") introduced a regression that due to the vma resource
> tracking of the binding state, dpt ptes were not correctly repopulated.
> Fix this by clearing the vma resource state before repopulating.
> The state will subsequently be restored by the bind_vma operation.
> 
> Fixes: 39a2bd34c933 ("drm/i915: Use the vma resource as argument for gtt binding / unbinding")
> Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Link: https://patchwork.freedesktop.org/patch/msgid/20220912121957.31310-1-thomas.hellstrom@linux.intel.com
> Cc: Matthew Auld <matthew.auld at intel.com>
> Cc: intel-gfx at lists.freedesktop.org
> Cc: <stable at vger.kernel.org> # v5.18+
> Reported-and-tested-by: Kevin Boulain <kevinboulain at gmail.com>
> Tested-by: David de Sousa <davidesousa at gmail.com>
> ---
>   drivers/gpu/drm/i915/gt/intel_ggtt.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> index b31fe0fb013f..5c67e49aacf6 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> @@ -1275,10 +1275,16 @@ bool i915_ggtt_resume_vm(struct i915_address_space *vm)
>   			atomic_read(&vma->flags) & I915_VMA_BIND_MASK;
>   
>   		GEM_BUG_ON(!was_bound);
> -		if (!retained_ptes)
> +		if (!retained_ptes) {
> +			/*
> +			 * Clear the bound flags of the vma resource to allow
> +			 * ptes to be repopulated.
> +			 */
> +			vma->resource->bound_flags = 0;

Personally I would put this at suspend path, if possible.
Anyway:
Reviewed-by: Andrzej Hajda <andrzej.hajda at intel.com>

Regards
Andrzej


>   			vma->ops->bind_vma(vm, NULL, vma->resource,
>   					   obj ? obj->cache_level : 0,
>   					   was_bound);
> +		}
>   		if (obj) { /* only used during resume => exclusive access */
>   			write_domain_objs |= fetch_and_zero(&obj->write_domain);
>   			obj->read_domains |= I915_GEM_DOMAIN_GTT;