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author | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2020-12-11 14:42:37 +0300 |
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committer | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2020-12-15 16:46:03 +0300 |
commit | 1b8977434606f2dcd8a90ca660eb535b56945662 (patch) | |
tree | c88f73abe2340fc120bd883418a03dc6b150b97d /drivers/gpu/drm/drm_fb_helper.c | |
parent | 6ca2ab8086af8434a4c0990882321a345c3cc2c6 (diff) | |
download | linux-1b8977434606f2dcd8a90ca660eb535b56945662.tar.xz |
drm: add legacy support for using degamma for gamma
The DRM core handles legacy gamma-set ioctl by setting GAMMA_LUT and
clearing CTM and DEGAMMA_LUT.
This works fine on HW where we have either:
degamma -> ctm -> gamma -> out
or
ctm -> gamma -> out
However, if the HW has gamma table before ctm, the atomic property
should be DEGAMMA_LUT, and thus we have:
degamma -> ctm -> out
This is fine for userspace which sets gamma table using the properties,
as the userspace can check for the existence of gamma & degamma, but the
legacy gamma-set ioctl does not work.
Change the DRM core to use DEGAMMA_LUT instead of GAMMA_LUT when the
latter is unavailable.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201211114237.213288-3-tomi.valkeinen@ti.com
Diffstat (limited to 'drivers/gpu/drm/drm_fb_helper.c')
-rw-r--r-- | drivers/gpu/drm/drm_fb_helper.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index e82db0f4e771..5ad19785daee 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1059,6 +1059,11 @@ retry: goto out_state; } + /* + * FIXME: This always uses gamma_lut. Some HW have only + * degamma_lut, in which case we should reset gamma_lut and set + * degamma_lut. See drm_crtc_legacy_gamma_set(). + */ replaced = drm_property_replace_blob(&crtc_state->degamma_lut, NULL); replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL); |