On 30/11/2020 12:38, Laurent Pinchart wrote:
- can be used when the driver exposes either only GAMMA_LUT or both GAMMA_LUT
- and DEGAMMA_LUT.
- */
+int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
u16 *red, u16 *green, u16 *blue,uint32_t size,struct drm_modeset_acquire_ctx *ctx)+{
- return legacy_gamma_degamma_set(crtc, red, green, blue, size, ctx, false);
+}
I wonder, would it make sense to make this automatic by setting the degamma LUT when only the DEGAMMA_LUT property exists, and the gamma LUT otherwise ? Are there use cases for drm_atomic_helper_legacy_degamma_set for drivers that support both gamma and degamma ?
Yes, I think drm_atomic_helper_legacy_gamma_set() could do that.
But if you look at the second patch, the driver deals with crtc_state->degamma_lut. Having .gamma_set = drm_atomic_helper_legacy_degamma_set makes it bit more explicit and clear what the driver is doing.
That said, documenting what drm_atomic_helper_legacy_gamma_set does if there's only degamma should also be clear enough, so... I don't have strong feelings either way =).
Tomi