Re: [PATCH v4 8/9] drm: rcar-du: kms: Update CMM in atomic commit tail

[Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>]

Hi Jacopo,

On 06/09/2019 14:54, 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.
> 
> When resuming from system suspend, the DU driver is responsible for
> reprogramming and enabling the CMM unit if it was in use at the time the
> system entered the suspend state.  Force the color_mgmt_changed flag to
> true if the DRM gamma lut color transformation property was set in the
> CRTC state duplicated at suspend time, as the CMM gets reprogrammed only
> if said flag is active in the rcar_du_atomic_commit_update_cmm() method.
> 
> Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

Also throwing in an LGTM here.

Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>



> ---
> 
> Daniel could you have a look if resume bits are worth being moved to the
> DRM core? The color_mgmt_changed flag is set to false when the state is
> duplicated if I read the code correctly, but when this happens in a
> suspend/resume sequence its value should probably be restored to true if
> any color management property was set in the crtc state when system entered
> suspend.
> 
> ---
> 
>  drivers/gpu/drm/rcar-du/rcar_du_drv.c | 20 ++++++++++++++
>  drivers/gpu/drm/rcar-du/rcar_du_kms.c | 38 +++++++++++++++++++++++++++
>  2 files changed, 58 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> index 018480a8f35c..d1003d31cfaf 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
> @@ -17,6 +17,7 @@
>  #include <linux/slab.h>
>  #include <linux/wait.h>
> 
> +#include <drm/drm_atomic.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_fb_cma_helper.h>
>  #include <drm/drm_fb_helper.h>
> @@ -482,6 +483,25 @@ static int rcar_du_pm_suspend(struct device *dev)
>  static int rcar_du_pm_resume(struct device *dev)
>  {
>  	struct rcar_du_device *rcdu = dev_get_drvdata(dev);
> +	struct drm_atomic_state *state = rcdu->ddev->mode_config.suspend_state;
> +	unsigned int i;
> +
> +	for (i = 0; i < rcdu->num_crtcs; ++i) {
> +		struct drm_crtc *crtc = &rcdu->crtcs[i].crtc;
> +		struct drm_crtc_state *crtc_state;
> +
> +		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
> +		if (!crtc_state)
> +			continue;
> +
> +		/*
> +		 * Force re-enablement of CMM after system resume if any
> +		 * of the DRM color transformation properties was set in
> +		 * the state saved at system suspend time.
> +		 */
> +		if (crtc_state->gamma_lut)
> +			crtc_state->color_mgmt_changed = true;
> +	}
> 
>  	return drm_mode_config_helper_resume(rcdu->ddev);
>  }
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> index 294630e56992..fc30fff0eb8d 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
> @@ -22,6 +22,7 @@
>  #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"
> @@ -368,6 +369,40 @@ 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 = {};
> +	struct device *dev = rcrtc->dev->dev;
> +	struct drm_property_blob *lut_blob;
> +
> +	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;
> +	}
> +
> +	lut_blob = crtc->state->gamma_lut;
> +	if (lut_blob->length != (CM2_LUT_SIZE * sizeof(struct drm_color_lut))) {
> +		/*
> +		 * We only accept fully populated LUT tables;
> +		 * be loud here, otherwise the CMM gets silently ignored.
> +		 */
> +		dev_err(dev, "invalid gamma lut size of %lu bytes\n",
> +			lut_blob->length);
> +		return;
> +	}
> +
> +	cmm_config.lut.enable = true;
> +	cmm_config.lut.table = (struct drm_color_lut *)lut_blob->data;
> +
> +	rcar_cmm_setup(rcrtc->cmm, &cmm_config);
> +}
> +
>  static int rcar_du_atomic_check(struct drm_device *dev,
>  				struct drm_atomic_state *state)
>  {
> @@ -410,6 +445,9 @@ 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,
> --
> 2.23.0
>