drm/exynos: fb: use drm_format_num_planes to get buffer count

The previous code had some special case handling for the buffer
count in exynos_drm_format_num_buffers().

This code was incorrect though, since this special case doesn't
exist for DRM. It stemmed from the existence of the special NV12M
V4L2 format. NV12 is a bi-planar format (separate planes for luma
and chroma) and V4L2 differentiates between a NV12 buffer where
luma and chroma is contiguous in memory (so no data between
luma/chroma), and a NV12 buffer where luma and chroma have two
explicit memory locations (which is then called NV12M).

This distinction doesn't exist for DRM. A bi-planar format always
explicitly comes with the information about its two planes (even
if these planes should be contiguous).

Signed-off-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Acked-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fb.c b/drivers/gpu/drm/exynos/exynos_drm_fb.c
index 929cb03..142eb4e 100644 (file)
--- a/drivers/gpu/drm/exynos/exynos_drm_fb.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fb.c
@@ -171,43 +171,6 @@ exynos_drm_framebuffer_init(struct drm_device *dev,
        return &exynos_fb->fb;
 }
 
-static u32 exynos_drm_format_num_buffers(struct drm_mode_fb_cmd2 *mode_cmd)
-{
-       unsigned int cnt = 0;
-
-       if (mode_cmd->pixel_format != DRM_FORMAT_NV12)
-               return drm_format_num_planes(mode_cmd->pixel_format);
-
-       while (cnt != MAX_FB_BUFFER) {
-               if (!mode_cmd->handles[cnt])
-                       break;
-               cnt++;
-       }
-
-       /*
-        * check if NV12 or NV12M.
-        *
-        * NV12
-        * handles[0] = base1, offsets[0] = 0
-        * handles[1] = base1, offsets[1] = Y_size
-        *
-        * NV12M
-        * handles[0] = base1, offsets[0] = 0
-        * handles[1] = base2, offsets[1] = 0
-        */
-       if (cnt == 2) {
-               /*
-                * in case of NV12 format, offsets[1] is not 0 and
-                * handles[0] is same as handles[1].
-                */
-               if (mode_cmd->offsets[1] &&
-                       mode_cmd->handles[0] == mode_cmd->handles[1])
-                       cnt = 1;
-       }
-
-       return cnt;
-}
-
 static struct drm_framebuffer *
 exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
                      struct drm_mode_fb_cmd2 *mode_cmd)
@@ -230,7 +193,7 @@ exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
 
        drm_helper_mode_fill_fb_struct(&exynos_fb->fb, mode_cmd);
        exynos_fb->exynos_gem_obj[0] = to_exynos_gem_obj(obj);
-       exynos_fb->buf_cnt = exynos_drm_format_num_buffers(mode_cmd);
+       exynos_fb->buf_cnt = drm_format_num_planes(mode_cmd->pixel_format);
 
        DRM_DEBUG_KMS("buf_cnt = %d\n", exynos_fb->buf_cnt);