Re: [PATCH v2 19/19] drm: rcar-du: kms: Update CMM in atomic commit tail

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Jacopo,

Thank you for the patch.

On Sat, Jul 06, 2019 at 04:07:46PM +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@jmondi.org>
> ---
>  drivers/gpu/drm/rcar-du/rcar_du_kms.c | 35 +++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> index b79cda2f5531..f9aece78ca5f 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"
> @@ -287,6 +288,37 @@ 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]);
> +	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)
>  {
> @@ -329,6 +361,9 @@ 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);
> +

I think this looks good overall, but I wonder if we couldn't simplify
the CMM driver suspend/resume and LUT caching due to config while not
enabled by handling it on the DU side. I have a rework on the commit
tail handler in progress, I'll think how this could be done. For now I
think you can leave it as is.

>  	/* Apply the atomic update. */
>  	drm_atomic_helper_commit_modeset_disables(dev, old_state);
>  	drm_atomic_helper_commit_planes(dev, old_state,

-- 
Regards,

Laurent Pinchart