Align pitch to multiples of 8 pixels for bpp values that do not map
to RGB formats. The call to drm_driver_color_mode_format() fails with
DRM_INVALID_FORMAT in these cases. Fall back to manually computing
the pitch alignment from which drm_mode_size_dumb() can compute the
correct pitch.

Fixes userspace that allocates dumb buffers for YUV formats, where
bpp equals 12. A common example is the IGT kms_getfb test.

Suggested-by: Dmitry Baryshkov <[email protected]>
Signed-off-by: Thomas Zimmermann <[email protected]>
Fixes: b1d0e470f881 ("drm/imx/ipuv3: Compute dumb-buffer sizes with 
drm_mode_size_dumb()")
Cc: Thomas Zimmermann <[email protected]>
Cc: Philipp Zabel <[email protected]>
Cc: Shawn Guo <[email protected]>
Cc: Sascha Hauer <[email protected]>
Cc: Pengutronix Kernel Team <[email protected]>
Cc: Fabio Estevam <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
This patch is based on Dmitry's fix for msm. [1] Please test.

There could later be a helper to contain these aligmentment calculations
in a single place.

[1] 
https://lore.kernel.org/dri-devel/[email protected]/
---
 drivers/gpu/drm/imx/ipuv3/imx-drm-core.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c 
b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
index 465b5a6ad5bb..5116f33a5973 100644
--- a/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
+++ b/drivers/gpu/drm/imx/ipuv3/imx-drm-core.c
@@ -144,7 +144,6 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
                               struct drm_mode_create_dumb *args)
 {
        u32 fourcc;
-       const struct drm_format_info *info;
        u64 pitch_align;
        int ret;
 
@@ -156,12 +155,15 @@ static int imx_drm_dumb_create(struct drm_file *file_priv,
         * the allocated buffer.
         */
        fourcc = drm_driver_color_mode_format(drm, args->bpp);
-       if (fourcc == DRM_FORMAT_INVALID)
-               return -EINVAL;
-       info = drm_format_info(fourcc);
-       if (!info)
-               return -EINVAL;
-       pitch_align = drm_format_info_min_pitch(info, 0, SZ_8);
+       if (fourcc != DRM_FORMAT_INVALID) {
+               const struct drm_format_info *info = drm_format_info(fourcc);
+
+               if (!info)
+                       return -EINVAL;
+               pitch_align = drm_format_info_min_pitch(info, 0, 8);
+       } else {
+               pitch_align = round_up(args->width, 8) * 
DIV_ROUND_UP(args->bpp, SZ_8);
+       }
        if (!pitch_align || pitch_align > U32_MAX)
                return -EINVAL;
        ret = drm_mode_size_dumb(drm, args, pitch_align, 0);
-- 
2.51.1

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