[PATCH v5 5/9] drm: Extend framebuffer_check to handle formats with cpp/char_per_block 0

[Brian Starkey]

Hi Alex,

On Fri, Oct 19, 2018 at 11:57:48AM +0100, Alexandru Gheorghe wrote:
>For formats that are supported only with non-linear modifiers it
>doesn't make to much sense to define cpp or char_per_block, so that
>will be set to 0.
>
>This patch adds a restriction to force having a modifier attached when
>cpp/char_per_block is 0, and to bypass checking the pitch restriction.
>
>This had been discussed here.
>[1] https://people.freedesktop.org/~cbrill/dri-log/?channel=dri-devel&highlight_names=&date=2018-09-13&show_html=true
>
>Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe at arm.com>
>---
> drivers/gpu/drm/drm_framebuffer.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
>index 6aca8a1ccdb6..e346d0ad92e0 100644
>--- a/drivers/gpu/drm/drm_framebuffer.c
>+++ b/drivers/gpu/drm/drm_framebuffer.c
>@@ -195,8 +195,13 @@ static int framebuffer_check(struct drm_device *dev,
> 	for (i = 0; i < info->num_planes; i++) {
> 		unsigned int width = fb_plane_width(r->width, info, i);
> 		unsigned int height = fb_plane_height(r->height, info, i);
>+		unsigned int block_size = info->char_per_block[i];
> 		u64 min_pitch = drm_format_info_min_pitch(info, i, width);
>
>+		if (!block_size && (r->modifier[i] == DRM_FORMAT_MOD_LINEAR)) {
>+			DRM_DEBUG_KMS("Format requires non-linear modifier for plane %d\n", i);
>+			return -EINVAL;
>+		}

You could probably move that blank like from Patch 2 to here ;-)
Otherwise LGTM:

Reviewed By: Brian Starkey <brian.starkey at arm.com>

> 		if (!r->handles[i]) {
> 			DRM_DEBUG_KMS("no buffer object handle for plane %d\n", i);
> 			return -EINVAL;
>@@ -208,7 +213,7 @@ static int framebuffer_check(struct drm_device *dev,
> 		if ((uint64_t) height * r->pitches[i] + r->offsets[i] > UINT_MAX)
> 			return -ERANGE;
>
>-		if (r->pitches[i] < min_pitch) {
>+		if (block_size && r->pitches[i] < min_pitch) {
> 			DRM_DEBUG_KMS("bad pitch %u for plane %d\n", r->pitches[i], i);
> 			return -EINVAL;
> 		}
>-- 
>2.18.0
>