[Intel-gfx] [PATCH 2/2] drm/i915: Try to handle 90/270 degree rotated initial fb

[Chris Wilson]

Quoting Ville Syrjala (2020-10-20 20:43:30)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Do the fb size readout correctly for the 90/270 degree rotated
> cases. Not sure if we're missing something else as well.
> 
> Also no idea whether the BIOS would ever do this.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 22 ++++++++++++--------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index fd0103f6cc95..183f5d3cd106 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -10604,7 +10604,7 @@ skl_get_initial_plane_config(struct intel_crtc *crtc,
>         enum pipe pipe;
>         u32 val, base, offset, stride_mult, tiling, alpha;
>         int fourcc, pixel_format;
> -       unsigned int aligned_height;
> +       unsigned int aligned_height, stride;
>         struct drm_framebuffer *fb;
>         struct intel_framebuffer *intel_fb;
>  
> @@ -10696,10 +10696,6 @@ skl_get_initial_plane_config(struct intel_crtc *crtc,
>             val & PLANE_CTL_FLIP_HORIZONTAL)
>                 plane_config->rotation |= DRM_MODE_REFLECT_X;
>  
> -       /* 90/270 degree rotation would require extra work */
> -       if (drm_rotation_90_or_270(plane_config->rotation))
> -               goto error;
> -
>         base = intel_de_read(dev_priv, PLANE_SURF(pipe, plane_id)) & 0xfffff000;
>         plane_config->base = base;
>  
> @@ -10710,10 +10706,18 @@ skl_get_initial_plane_config(struct intel_crtc *crtc,
>         fb->width = ((val >> 0) & 0xffff) + 1;
>  
>         val = intel_de_read(dev_priv, PLANE_STRIDE(pipe, plane_id));
> -       stride_mult = skl_plane_stride_mult(fb, 0, DRM_MODE_ROTATE_0);
> -       fb->pitches[0] = (val & 0x3ff) * stride_mult;
> -
> -       aligned_height = intel_fb_align_height(fb, 0, fb->height);
> +       stride_mult = skl_plane_stride_mult(fb, 0, plane_config->rotation);
> +       stride = (val & 0x3ff) * stride_mult;
> +
> +       if (drm_rotation_90_or_270(plane_config->rotation)) {
> +               swap(fb->width, fb->height);
> +               fb->pitches[0] = ALIGN(fb->width * fb->format->cpp[0],
> +                                      intel_fb_stride_alignment(fb, 0));
> +               aligned_height = stride;
> +       } else {
> +               fb->pitches[0] = stride;
> +               aligned_height = intel_fb_align_height(fb, 0, fb->height);
> +       }

Cross check with tiling-y to rule out garbage?

We could also check the stride is suitable for tiling. How much do you
trust that the registers light up a plane?
-Chris