Re: [PATCH v2] drm/sun4i: sun8i: Avoid clearing blending order at each atomic commit
From: Paul Kocialkowski
Date: Tue Jul 17 2018 - 09:58:50 EST
On Tue, 2018-07-17 at 14:25 +0200, Paul Kocialkowski wrote:
> Blending order is set based on the z position of each DRM plane. The
> blending order register is currently cleared at each atomic DRM commit,
> with the intent that each committed plane will set the appropriate
> bits (based on its z-pos) when enabling the plane.
>
> However, it sometimes happens that a particular plane is left unchanged
> by an atomic commit and thus will not be configured again. In that
> scenario, blending order is cleared and only the bits relevant for the
> planes affected by the commit are set. This leaves the planes that did
> not change without their blending order set in the register, leading
> to that plane not being displayed.
>
> Instead of clearing the blending order register at every atomic commit,
> this change moves the register's initial clear at bind time and only
> clears the bits for a specific plane when disabling it or changing its
> zpos.
>
> This way, planes that are left untouched by a DRM atomic commit are
> no longer disabled.
This patch was rebased to apply on top of DRM misc. V1 had been based on
the first revision of the DE2 z-pos support patch, while a subsequent
revision of the patch made it to the kernel tree.
Cheers!
Paul
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/sun4i/sun8i_mixer.c | 15 +++------------
> drivers/gpu/drm/sun4i/sun8i_ui_layer.c | 24 ++++++++++++++++++++----
> drivers/gpu/drm/sun4i/sun8i_vi_layer.c | 24 ++++++++++++++++++++----
> 3 files changed, 43 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.c b/drivers/gpu/drm/sun4i/sun8i_mixer.c
> index 8e81c24d736e..12cb7183ce51 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_mixer.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
> @@ -260,17 +260,6 @@ const struct de2_fmt_info *sun8i_mixer_format_info(u32 format)
> return NULL;
> }
>
> -static void sun8i_mixer_atomic_begin(struct sunxi_engine *engine,
> - struct drm_crtc_state *old_state)
> -{
> - /*
> - * Disable all pipes at the beginning. They will be enabled
> - * again if needed in plane update callback.
> - */
> - regmap_update_bits(engine->regs, SUN8I_MIXER_BLEND_PIPE_CTL,
> - SUN8I_MIXER_BLEND_PIPE_CTL_EN_MSK, 0);
> -}
> -
> static void sun8i_mixer_commit(struct sunxi_engine *engine)
> {
> DRM_DEBUG_DRIVER("Committing changes\n");
> @@ -322,7 +311,6 @@ static struct drm_plane **sun8i_layers_init(struct drm_device *drm,
> }
>
> static const struct sunxi_engine_ops sun8i_engine_ops = {
> - .atomic_begin = sun8i_mixer_atomic_begin,
> .commit = sun8i_mixer_commit,
> .layers_init = sun8i_layers_init,
> };
> @@ -449,6 +437,9 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master,
> regmap_write(mixer->engine.regs, SUN8I_MIXER_BLEND_MODE(i),
> SUN8I_MIXER_BLEND_MODE_DEF);
>
> + regmap_update_bits(mixer->engine.regs, SUN8I_MIXER_BLEND_PIPE_CTL,
> + SUN8I_MIXER_BLEND_PIPE_CTL_EN_MSK, 0);
> +
> return 0;
>
> err_disable_bus_clk:
> diff --git a/drivers/gpu/drm/sun4i/sun8i_ui_layer.c b/drivers/gpu/drm/sun4i/sun8i_ui_layer.c
> index 518e1921f47e..28c15c6ef1ef 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_ui_layer.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_ui_layer.c
> @@ -27,7 +27,8 @@
> #include "sun8i_ui_scaler.h"
>
> static void sun8i_ui_layer_enable(struct sun8i_mixer *mixer, int channel,
> - int overlay, bool enable, unsigned int zpos)
> + int overlay, bool enable, unsigned int zpos,
> + unsigned int old_zpos)
> {
> u32 val;
>
> @@ -43,6 +44,18 @@ static void sun8i_ui_layer_enable(struct sun8i_mixer *mixer, int channel,
> SUN8I_MIXER_CHAN_UI_LAYER_ATTR(channel, overlay),
> SUN8I_MIXER_CHAN_UI_LAYER_ATTR_EN, val);
>
> + if (!enable || zpos != old_zpos) {
> + regmap_update_bits(mixer->engine.regs,
> + SUN8I_MIXER_BLEND_PIPE_CTL,
> + SUN8I_MIXER_BLEND_PIPE_CTL_EN(old_zpos),
> + 0);
> +
> + regmap_update_bits(mixer->engine.regs,
> + SUN8I_MIXER_BLEND_ROUTE,
> + SUN8I_MIXER_BLEND_ROUTE_PIPE_MSK(old_zpos),
> + 0);
> + }
> +
> if (enable) {
> val = SUN8I_MIXER_BLEND_PIPE_CTL_EN(zpos);
>
> @@ -242,9 +255,11 @@ static void sun8i_ui_layer_atomic_disable(struct drm_plane *plane,
> struct drm_plane_state *old_state)
> {
> struct sun8i_ui_layer *layer = plane_to_sun8i_ui_layer(plane);
> + unsigned int old_zpos = old_state->normalized_zpos;
> struct sun8i_mixer *mixer = layer->mixer;
>
> - sun8i_ui_layer_enable(mixer, layer->channel, layer->overlay, false, 0);
> + sun8i_ui_layer_enable(mixer, layer->channel, layer->overlay, false, 0,
> + old_zpos);
> }
>
> static void sun8i_ui_layer_atomic_update(struct drm_plane *plane,
> @@ -252,11 +267,12 @@ static void sun8i_ui_layer_atomic_update(struct drm_plane *plane,
> {
> struct sun8i_ui_layer *layer = plane_to_sun8i_ui_layer(plane);
> unsigned int zpos = plane->state->normalized_zpos;
> + unsigned int old_zpos = old_state->normalized_zpos;
> struct sun8i_mixer *mixer = layer->mixer;
>
> if (!plane->state->visible) {
> sun8i_ui_layer_enable(mixer, layer->channel,
> - layer->overlay, false, 0);
> + layer->overlay, false, 0, old_zpos);
> return;
> }
>
> @@ -267,7 +283,7 @@ static void sun8i_ui_layer_atomic_update(struct drm_plane *plane,
> sun8i_ui_layer_update_buffer(mixer, layer->channel,
> layer->overlay, plane);
> sun8i_ui_layer_enable(mixer, layer->channel, layer->overlay,
> - true, zpos);
> + true, zpos, old_zpos);
> }
>
> static struct drm_plane_helper_funcs sun8i_ui_layer_helper_funcs = {
> diff --git a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> index 17e0d00cfd8a..f4fe97813f94 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> @@ -21,7 +21,8 @@
> #include "sun8i_vi_scaler.h"
>
> static void sun8i_vi_layer_enable(struct sun8i_mixer *mixer, int channel,
> - int overlay, bool enable, unsigned int zpos)
> + int overlay, bool enable, unsigned int zpos,
> + unsigned int old_zpos)
> {
> u32 val;
>
> @@ -37,6 +38,18 @@ static void sun8i_vi_layer_enable(struct sun8i_mixer *mixer, int channel,
> SUN8I_MIXER_CHAN_VI_LAYER_ATTR(channel, overlay),
> SUN8I_MIXER_CHAN_VI_LAYER_ATTR_EN, val);
>
> + if (!enable || zpos != old_zpos) {
> + regmap_update_bits(mixer->engine.regs,
> + SUN8I_MIXER_BLEND_PIPE_CTL,
> + SUN8I_MIXER_BLEND_PIPE_CTL_EN(old_zpos),
> + 0);
> +
> + regmap_update_bits(mixer->engine.regs,
> + SUN8I_MIXER_BLEND_ROUTE,
> + SUN8I_MIXER_BLEND_ROUTE_PIPE_MSK(old_zpos),
> + 0);
> + }
> +
> if (enable) {
> val = SUN8I_MIXER_BLEND_PIPE_CTL_EN(zpos);
>
> @@ -270,9 +283,11 @@ static void sun8i_vi_layer_atomic_disable(struct drm_plane *plane,
> struct drm_plane_state *old_state)
> {
> struct sun8i_vi_layer *layer = plane_to_sun8i_vi_layer(plane);
> + unsigned int old_zpos = old_state->normalized_zpos;
> struct sun8i_mixer *mixer = layer->mixer;
>
> - sun8i_vi_layer_enable(mixer, layer->channel, layer->overlay, false, 0);
> + sun8i_vi_layer_enable(mixer, layer->channel, layer->overlay, false, 0,
> + old_zpos);
> }
>
> static void sun8i_vi_layer_atomic_update(struct drm_plane *plane,
> @@ -280,11 +295,12 @@ static void sun8i_vi_layer_atomic_update(struct drm_plane *plane,
> {
> struct sun8i_vi_layer *layer = plane_to_sun8i_vi_layer(plane);
> unsigned int zpos = plane->state->normalized_zpos;
> + unsigned int old_zpos = old_state->normalized_zpos;
> struct sun8i_mixer *mixer = layer->mixer;
>
> if (!plane->state->visible) {
> sun8i_vi_layer_enable(mixer, layer->channel,
> - layer->overlay, false, 0);
> + layer->overlay, false, 0, old_zpos);
> return;
> }
>
> @@ -295,7 +311,7 @@ static void sun8i_vi_layer_atomic_update(struct drm_plane *plane,
> sun8i_vi_layer_update_buffer(mixer, layer->channel,
> layer->overlay, plane);
> sun8i_vi_layer_enable(mixer, layer->channel, layer->overlay,
> - true, zpos);
> + true, zpos, old_zpos);
> }
>
> static struct drm_plane_helper_funcs sun8i_vi_layer_helper_funcs = {
--
Paul Kocialkowski, Bootlin (formerly Free Electrons)
Embedded Linux and kernel engineering
https://bootlin.comAttachment:
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