On Wed, Nov 23, 2022 at 05:43:10PM +0100, Geert Uytterhoeven wrote:
> As of commit eae06120f1974e1a ("drm: refuse ADDFB2 ioctl for broken
> bigendian drivers"), drivers must set the
> quirk_addfb_prefer_host_byte_order quirk to make the drm_mode_addfb()
> compat code work correctly on big-endian machines.
>
> While that works fine for big-endian XRGB8888 and ARGB8888, which are
> mapped to the existing little-endian BGRX8888 and BGRA8888 formats, it
> does not work for big-endian XRGB1555 and RGB565, as the latter are not
> listed in the format database.
>
> Fix this by adding the missing formats. Limit this to big-endian
> platforms, as there is currently no need to support these formats on
> little-endian platforms.
>
> Fixes: 6960e6da9cec3f66 ("drm: fix drm_mode_addfb() on big endian machines.")
> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> v2:
> - Use "DRM_FORMAT_foo | DRM_FORMAT_BIG_ENDIAN" instead of
> "DRM_FORMAT_HOST_foo",
> - Turn into a lone patch, as all other patches from series
> https://lore.kernel.org/r/cover.1657300532.git.geert@xxxxxxxxxxxxxx
> were applied to drm-misc/for-linux-next.
> ---
> drivers/gpu/drm/drm_fourcc.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index e09331bb3bc73f21..265671a7f9134c1f 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -190,6 +190,10 @@ const struct drm_format_info *__drm_format_info(u32 format)
> { .format = DRM_FORMAT_BGRA5551, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1, .has_alpha = true },
> { .format = DRM_FORMAT_RGB565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
> { .format = DRM_FORMAT_BGR565, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
> +#ifdef __BIG_ENDIAN
Why do we need the #ifdef here? Iirc some hw has big endian flags in the
scanout registers, so could supprt this unconditionally if there's no
#ifdef around the format defines. Some drivers might then also want a
DRM_FORMAT_FOO_BE define to simplify tables and stuff, but that's more a
bikeshed.
Otherwise this makes sense to me.
-Daniel
> + { .format = DRM_FORMAT_XRGB1555 | DRM_FORMAT_BIG_ENDIAN, .depth = 15, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
> + { .format = DRM_FORMAT_RGB565 | DRM_FORMAT_BIG_ENDIAN, .depth = 16, .num_planes = 1, .cpp = { 2, 0, 0 }, .hsub = 1, .vsub = 1 },
> +#endif
> { .format = DRM_FORMAT_RGB888, .depth = 24, .num_planes = 1, .cpp = { 3, 0, 0 }, .hsub = 1, .vsub = 1 },
> { .format = DRM_FORMAT_BGR888, .depth = 24, .num_planes = 1, .cpp = { 3, 0, 0 }, .hsub = 1, .vsub = 1 },
> { .format = DRM_FORMAT_XRGB8888, .depth = 24, .num_planes = 1, .cpp = { 4, 0, 0 }, .hsub = 1, .vsub = 1 },
> --
> 2.25.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
