On Saturday, August 29, 2020 4:06 PM, Sidong Yang <realwa...@gmail.com> wrote:
> Currently vkms module doesn't support gamma function for userspace. so igt
> subtests in kms_plane(pixel-format-pipe-A-plan) failed for calling
> drmModeCrtcSetGamma().
It doesn't seem like this IGT test's goal is to exercise support for
gamma LUTs. Does the test just tries to reset the gamma LUT to linear?
If so, I think the IGT test should be fixed to ignore "I don't support
gamma" errors.
> This patch set gamma_set interface in vkms_crtc_funcs for
> support gamma function. With initializing crtc, added calls for setting gamma
> size. it pass the test after this patch.
>
> Cc: Daniel Vetter<dan...@ffwll.ch>
> Cc: Rodrigo Siqueira <rodrigosiqueiram...@gmail.com>
> Cc: Haneen Mohammed <hamohammed...@gmail.com>
>
> Signed-off-by: Sidong Yang <realwa...@gmail.com>
> ---
> drivers/gpu/drm/vkms/vkms_crtc.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c
> b/drivers/gpu/drm/vkms/vkms_crtc.c
> index ac85e17428f8..643435fb2ee6 100644
> --- a/drivers/gpu/drm/vkms/vkms_crtc.c
> +++ b/drivers/gpu/drm/vkms/vkms_crtc.c
> @@ -160,6 +160,7 @@ static const struct drm_crtc_funcs vkms_crtc_funcs = {
> .get_crc_sources = vkms_get_crc_sources,
> .set_crc_source = vkms_set_crc_source,
> .verify_crc_source = vkms_verify_crc_source,
> + .gamma_set = drm_atomic_helper_legacy_gamma_set,
Why does VKMS need to use a legacy helper?
It seems like this patch just advertises support for gamma LUTs, but
ignores any value set by user-space. If VKMS advertises support for
gamma LUTs, it needs to take the LUT into account when blending planes.
> };
>
> static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
> @@ -275,6 +276,13 @@ int vkms_crtc_init(struct drm_device *dev, struct
> drm_crtc *crtc,
> return ret;
> }
>
> + ret = drm_mode_crtc_set_gamma_size(crtc, 256);
> + if (ret) {
> + DRM_ERROR("Failed to set gamma size\n");
> + return ret;
> + }
> + drm_crtc_enable_color_mgmt(crtc, 0, false, 256);
> +
> drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
>
> spin_lock_init(&vkms_out->lock);
> --
> 2.17.1
