[Intel-gfx] [PATCH] drm/i915: Check fb stride against plane max stride

[Dhinakaran Pandiyan]

On Tuesday, September 18, 2018 7:02:43 AM PDT Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> commit 4e0b83a567e2 ("drm/i915: Extract per-platform plane->check()
> functions") removed the plane max stride check for sprite planes.
> I was going to add it back when introducing GTT remapping for the
> display, but after further thought it seems better to re-introduce
> it separately.
> 
> So let's add the max stride check back. And let's do it in a nicer
> form than what we had before and do it for all plane types (easy
> now that we have the ->max_stride() plane vfunc).
> 
> Only sprite planes really need this for now since primary planes
> are capable of scanning out the current max fb size we allow, and
> cursors have more stringent stride checks elsewhere.
> 
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Fixes: 4e0b83a567e2 ("drm/i915: Extract per-platform plane->check()
> functions") Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 14 ++++++++++++++
>  drivers/gpu/drm/i915/intel_drv.h     |  1 +
>  drivers/gpu/drm/i915/intel_sprite.c  | 22 ++++++++++++++++++++++
>  3 files changed, 37 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c
> b/drivers/gpu/drm/i915/intel_display.c index eb25037d7b38..1eb99d5ec221
> 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3151,6 +3151,10 @@ int skl_check_plane_surface(struct intel_plane_state
> *plane_state) plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0,
> rotation); plane_state->color_plane[1].stride = intel_fb_pitch(fb, 1,
> rotation);
> 
> +	ret = intel_plane_check_stride(plane_state);
> +	if (ret)
> +		return ret;
> +
>  	if (!plane_state->base.visible)
>  		return 0;
> 
> @@ -3286,10 +3290,15 @@ int i9xx_check_plane_surface(struct
> intel_plane_state *plane_state) int src_x = plane_state->base.src.x1 >> 16;
>  	int src_y = plane_state->base.src.y1 >> 16;
>  	u32 offset;
> +	int ret;
> 
>  	intel_fill_fb_ggtt_view(&plane_state->view, fb, rotation);
>  	plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0, rotation);
> 
Is there a good reason to not  inline the code ?
	if (color_plane[0].stride > plane->max_stride())
		return -EINVAL;


> +	ret = intel_plane_check_stride(plane_state);
> +	if (ret)
> +		return ret;
> +
>  	intel_add_fb_offsets(&src_x, &src_y, plane_state, 0);
> 
>  	if (INTEL_GEN(dev_priv) >= 4)
> @@ -9685,10 +9694,15 @@ static int intel_cursor_check_surface(struct
> intel_plane_state *plane_state) unsigned int rotation =
> plane_state->base.rotation;
>  	int src_x, src_y;
>  	u32 offset;
> +	int ret;
> 
>  	intel_fill_fb_ggtt_view(&plane_state->view, fb, rotation);
>  	plane_state->color_plane[0].stride = intel_fb_pitch(fb, 0, rotation);
> 
> +	ret = intel_plane_check_stride(plane_state);
> +	if (ret)
> +		return ret;
> +
>  	src_x = plane_state->base.src_x >> 16;
>  	src_y = plane_state->base.src_y >> 16;
> 
> diff --git a/drivers/gpu/drm/i915/intel_drv.h
> b/drivers/gpu/drm/i915/intel_drv.h index bf1c38728a59..a34c2f1f9159 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -2140,6 +2140,7 @@ unsigned int skl_plane_max_stride(struct intel_plane
> *plane, unsigned int rotation);
>  int skl_plane_check(struct intel_crtc_state *crtc_state,
>  		    struct intel_plane_state *plane_state);
> +int intel_plane_check_stride(const struct intel_plane_state *plane_state);
>  int intel_plane_check_src_coordinates(struct intel_plane_state
> *plane_state); int chv_plane_check_rotation(const struct intel_plane_state
> *plane_state);
> 
> diff --git a/drivers/gpu/drm/i915/intel_sprite.c
> b/drivers/gpu/drm/i915/intel_sprite.c index d4c8e10fc90b..5fd2f7bf3927
> 100644
> --- a/drivers/gpu/drm/i915/intel_sprite.c
> +++ b/drivers/gpu/drm/i915/intel_sprite.c
> @@ -230,6 +230,28 @@ void intel_pipe_update_end(struct intel_crtc_state
> *new_crtc_state) #endif
>  }
> 
> +int intel_plane_check_stride(const struct intel_plane_state *plane_state)
> +{
> +	struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
> +	const struct drm_framebuffer *fb = plane_state->base.fb;
> +	unsigned int rotation = plane_state->base.rotation;
> +	u32 stride, max_stride;
> +
> +	/* FIXME other color planes? */
Doesn't the color plane 0 have the max stride always?


> +	stride = plane_state->color_plane[0].stride;
> +	max_stride = plane->max_stride(plane, fb->format->format,
> +				       fb->modifier, rotation);
> +
> +	if (stride > max_stride) {
> +		DRM_DEBUG_KMS("[FB:%d] stride (%d) exceeds [PLANE:%d:%s] max stride
> (%d)\n", +			      fb->base.id, stride,
> +			      plane->base.base.id, plane->base.name, max_stride);
Include the color plane number in the debug print?

> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  int intel_plane_check_src_coordinates(struct intel_plane_state
> *plane_state) {
>  	const struct drm_framebuffer *fb = plane_state->base.fb;