Re: [PATCH v6 29/30] drm/rockchip: Disallow PSR for the whole atomic commit

[Andrzej Hajda <a.hajda@samsung.com>]

On 05.04.2018 11:49, Enric Balletbo i Serra wrote:
> From: Tomasz Figa <tfiga@chromium.org>
>
> Currently PSR flush is triggered from CRTC's .atomic_begin() callback,
> which is executed after modeset disables and enables and before plane
> updates are committed. Since PSR flush and re-enable can be triggered
> asynchronously by external sources (input event, delayed work), it can
> race with hardware programming done in the aforementioned stages.
>
> This patch blocks the PSR completely before hardware programming part
> begins and unblock after it ends. This relies on reference counted PSR
> disable introduced with previous patch.
>
> Cc: Kristian H. Kristensen <hoegsberg@chromium.org>
> Signed-off-by: Tomasz Figa <tfiga@chromium.org>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>
>  drivers/gpu/drm/rockchip/rockchip_drm_fb.c  | 61 ++++++++++++++++++++++++++++-
>  drivers/gpu/drm/rockchip/rockchip_drm_vop.c |  7 ----
>  2 files changed, 60 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> index e266539e04e5..d4f4118b482d 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
> @@ -167,8 +167,67 @@ rockchip_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
>  	return ERR_PTR(ret);
>  }
>  
> +static void
> +rockchip_drm_psr_inhibit_get_state(struct drm_atomic_state *state)
> +{
> +	struct drm_crtc *crtc;
> +	struct drm_crtc_state *crtc_state;
> +	struct drm_encoder *encoder;
> +	u32 encoder_mask = 0;
> +	int i;
> +
> +	for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
> +		encoder_mask |= crtc_state->encoder_mask;
> +		encoder_mask |= crtc->state->encoder_mask;

Looks clever and cryptic. More readable would be with
for_each_oldnew_crtc_in_state.
Anyway:
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

 --
Regards
Andrzej

> +	}
> +
> +	drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
> +		rockchip_drm_psr_inhibit_get(encoder);
> +}
> +
> +static void
> +rockchip_drm_psr_inhibit_put_state(struct drm_atomic_state *state)
> +{
> +	struct drm_crtc *crtc;
> +	struct drm_crtc_state *crtc_state;
> +	struct drm_encoder *encoder;
> +	u32 encoder_mask = 0;
> +	int i;
> +
> +	for_each_old_crtc_in_state(state, crtc, crtc_state, i) {
> +		encoder_mask |= crtc_state->encoder_mask;
> +		encoder_mask |= crtc->state->encoder_mask;
> +	}
> +
> +	drm_for_each_encoder_mask(encoder, state->dev, encoder_mask)
> +		rockchip_drm_psr_inhibit_put(encoder);
> +}
> +
> +static void
> +rockchip_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state)
> +{
> +	struct drm_device *dev = old_state->dev;
> +
> +	rockchip_drm_psr_inhibit_get_state(old_state);
> +
> +	drm_atomic_helper_commit_modeset_disables(dev, old_state);
> +
> +	drm_atomic_helper_commit_modeset_enables(dev, old_state);
> +
> +	drm_atomic_helper_commit_planes(dev, old_state,
> +					DRM_PLANE_COMMIT_ACTIVE_ONLY);
> +
> +	rockchip_drm_psr_inhibit_put_state(old_state);
> +
> +	drm_atomic_helper_commit_hw_done(old_state);
> +
> +	drm_atomic_helper_wait_for_vblanks(dev, old_state);
> +
> +	drm_atomic_helper_cleanup_planes(dev, old_state);
> +}
> +
>  static const struct drm_mode_config_helper_funcs rockchip_mode_config_helpers = {
> -	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
> +	.atomic_commit_tail = rockchip_atomic_helper_commit_tail_rpm,
>  };
>  
>  static const struct drm_mode_config_funcs rockchip_drm_mode_config_funcs = {
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index 00f7f3441cf6..f14a10ca4792 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -1029,16 +1029,9 @@ static void vop_crtc_atomic_flush(struct drm_crtc *crtc,
>  	}
>  }
>  
> -static void vop_crtc_atomic_begin(struct drm_crtc *crtc,
> -				  struct drm_crtc_state *old_crtc_state)
> -{
> -	rockchip_drm_psr_flush(crtc);
> -}
> -
>  static const struct drm_crtc_helper_funcs vop_crtc_helper_funcs = {
>  	.mode_fixup = vop_crtc_mode_fixup,
>  	.atomic_flush = vop_crtc_atomic_flush,
> -	.atomic_begin = vop_crtc_atomic_begin,
>  	.atomic_enable = vop_crtc_atomic_enable,
>  	.atomic_disable = vop_crtc_atomic_disable,
>  };