Re: [PATCH 20/20] drm: rcar-du: kms: Update CMM in atomic commit tail

From: Laurent Pinchart
Date: Thu Sep 12 2019 - 19:40:23 EST


Hi Jacopo,

On Fri, Jun 14, 2019 at 10:19:13AM +0200, Jacopo Mondi wrote:
> On Fri, Jun 07, 2019 at 03:06:33PM +0300, Laurent Pinchart wrote:
> > On Thu, Jun 06, 2019 at 04:22:20PM +0200, Jacopo Mondi wrote:
> >> Update CMM settings at in the atomic commit tail helper method.
> >>
> >> The CMM is updated with new gamma values provided to the driver
> >> in the GAMMA_LUT blob property.
> >>
> >> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> >> ---
> >> drivers/gpu/drm/rcar-du/rcar_du_kms.c | 36 +++++++++++++++++++++++++++
> >> 1 file changed, 36 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> >> index 5a910a04e1d9..29a2020a46b5 100644
> >> --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> >> +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> >> @@ -21,6 +21,7 @@
> >> #include <linux/of_platform.h>
> >> #include <linux/wait.h>
> >>
> >> +#include "rcar_cmm.h"
> >> #include "rcar_du_crtc.h"
> >> #include "rcar_du_drv.h"
> >> #include "rcar_du_encoder.h"
> >> @@ -367,6 +368,38 @@ rcar_du_fb_create(struct drm_device *dev, struct drm_file *file_priv,
> >> * Atomic Check and Update
> >> */
> >>
> >> +static void rcar_du_atomic_commit_update_cmm(struct drm_crtc *crtc,
> >> + struct drm_crtc_state *old_state)
> >> +{
> >> + struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
> >> + struct rcar_cmm_config cmm_config = {};
> >> +
> >> + if (!rcrtc->cmm || !crtc->state->color_mgmt_changed)
> >> + return;
> >> +
> >> + if (!crtc->state->gamma_lut) {
> >> + cmm_config.lut.enable = false;
> >> + rcar_cmm_setup(rcrtc->cmm, &cmm_config);
> >> +
> >> + return;
> >> + }
> >> +
> >> + cmm_config.lut.enable = true;
> >> + cmm_config.lut.table = (struct drm_color_lut *)
> >> + crtc->state->gamma_lut->data;
> >> +
> >> + /* Set LUT table size to 0 if entries should not be updated. */
> >> + if (!old_state->gamma_lut ||
> >> + (old_state->gamma_lut->base.id !=
> >> + crtc->state->gamma_lut->base.id))
> >> + cmm_config.lut.size = crtc->state->gamma_lut->length
> >> + / sizeof(cmm_config.lut.table[0]);
> >
> > Do you need to call rcar_cmm_setup() at all in this case ?
>
> Do you mean in case the lut.size field is set to 0 ?
> I considered it useful when the CMM has to be re-enabled without
> updateing the LUT table entries? It is not required in your opinion?

You're right, I thought userspace couldn't do this, but it actually can.

> >> + else
> >> + cmm_config.lut.size = 0;
> >> +
> >> + rcar_cmm_setup(rcrtc->cmm, &cmm_config);
> >> +}
> >> +
> >> static int rcar_du_atomic_check(struct drm_device *dev,
> >> struct drm_atomic_state *state)
> >> {
> >> @@ -409,6 +442,9 @@ static void rcar_du_atomic_commit_tail(struct drm_atomic_state *old_state)
> >> rcdu->dpad1_source = rcrtc->index;
> >> }
> >>
> >> + for_each_old_crtc_in_state(old_state, crtc, crtc_state, i)
> >> + rcar_du_atomic_commit_update_cmm(crtc, crtc_state);
> >> +
> >> /* Apply the atomic update. */
> >> drm_atomic_helper_commit_modeset_disables(dev, old_state);
> >> drm_atomic_helper_commit_planes(dev, old_state,

--
Regards,

Laurent Pinchart