[Intel-gfx] [PATCH v2 07/10] drm/i915/adl_p: Add stride restriction when using DPT

[Clint Taylor]

On 5/6/21 9:19 AM, Imre Deak wrote:
> From: José Roberto de Souza <jose.souza at intel.com>
>
> Alderlake-P have a new stride restriction when using DPT and it is used
> by non linear framebuffers. Stride needs to be a power of two to take
> full DPT rows, but stride is a parameter set by userspace.
>
> What we could do is use a fake stride when doing DPT allocation so
> HW requirements are met and userspace don't need to be changed to
> met this power of two restrictions but this change will take a while
> to be implemented so for now adding this restriction in driver to
> reject atomic commits that would cause visual corruptions.
>
> BSpec: 53393
> Acked-by: Matt Roper <matthew.d.roper at intel.com>
> Cc: Matt Roper <matthew.d.roper at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>   drivers/gpu/drm/i915/display/intel_display.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 292396058e75d..70ac197746b1f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -11566,6 +11566,15 @@ static int intel_framebuffer_init(struct intel_framebuffer *intel_fb,
>   			}
>   		}
>   
> +		if (IS_ALDERLAKE_P(dev_priv) &&
> +		    mode_cmd->modifier[i] != DRM_FORMAT_MOD_LINEAR &&
> +		    !is_power_of_2(mode_cmd->pitches[i])) {
> +			drm_dbg_kms(&dev_priv->drm,
> +				    "plane %d pitch (%d) must be power of two for tiled buffers\n",
> +				    i, mode_cmd->pitches[i]);
> +			goto err;
> +		}
> +
Reviewed-by: Clint Taylor <Clinton.A.Taylor at intel.com>
>   		fb->obj[i] = &obj->base;
>   	}
>