Re: [PATCH v1 4/6] drm/mediatek: update cursors by using async atomic update

Hi, Bibby:

On Thu, 2019-11-28 at 10:42 +0800, Bibby Hsieh wrote:

Support to async updates of cursors by using the new atomic interface for that.

Signed-off-by: Bibby Hsieh bibby.hsieh@mediatek.com

drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 35 +++++++++++++++++ drivers/gpu/drm/mediatek/mtk_drm_crtc.h | 2 + drivers/gpu/drm/mediatek/mtk_drm_drv.c | 22 ++++++++++- drivers/gpu/drm/mediatek/mtk_drm_drv.h | 2 + drivers/gpu/drm/mediatek/mtk_drm_plane.c | 50 ++++++++++++++++++++++++ drivers/gpu/drm/mediatek/mtk_drm_plane.h | 2 + 6 files changed, 112 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c index cb87a538b8ff..b26b7a98587b 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c @@ -422,6 +422,41 @@ int mtk_drm_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane, return 0; }

+void mtk_drm_crtc_cursor_update(struct drm_crtc *crtc, struct drm_plane *plane,

• 		struct drm_plane_state *new_state)
  

I do not like to use 'cursor' for naming. The async function may be not just used for cursor. The name 'async' is more general.

+{

• struct mtk_drm_private *priv = crtc->dev->dev_private;
• struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
• const struct drm_plane_helper_funcs *plane_helper_funcs =

• 	plane->helper_private;
  

• int i;
• if (!mtk_crtc->enabled)

• return;
  

• mutex_lock(&priv->hw_lock);

Please make sure what variable you want to protect, and make critical section smaller.

• plane_helper_funcs->atomic_update(plane, new_state);
• for (i = 0; i < mtk_crtc->layer_nr; i++) {

• struct drm_plane *plane = &mtk_crtc->planes[i];
  

• struct mtk_plane_state *plane_state;
  

• plane_state = to_mtk_plane_state(plane->state);
  

• if (plane_state->pending.cursor_dirty) {
  

• 	plane_state->pending.config = true;
  

• 	plane_state->pending.cursor_update = false;
  

• 	plane_state->pending.cursor_dirty = false;
  

• }
  

• }
• mtk_crtc->pending_planes = true;
• if (priv->data->shadow_register) {

• mtk_disp_mutex_acquire(mtk_crtc->mutex);
  

• mtk_crtc_ddp_config(crtc);
  

• mtk_disp_mutex_release(mtk_crtc->mutex);
  

• }
• mutex_unlock(&priv->hw_lock);

+}

static void mtk_drm_crtc_atomic_enable(struct drm_crtc *crtc, struct drm_crtc_state *old_state) { diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h index 6afe1c19557a..d57958f0b7b5 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.h +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.h @@ -21,5 +21,7 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev, unsigned int path_len); int mtk_drm_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane, struct mtk_plane_state *state); +void mtk_drm_crtc_cursor_update(struct drm_crtc *crtc, struct drm_plane *plane,

• 		struct drm_plane_state *plane_state);
  
  

#endif /* MTK_DRM_CRTC_H */ diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index 16e5771d182e..0f7fbb68295d 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -36,8 +36,27 @@ #define DRIVER_MAJOR 1 #define DRIVER_MINOR 0

+static void +mtk_drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state) +{

• struct drm_device *dev = old_state->dev;
• struct mtk_drm_private *private = dev->dev_private;
• drm_atomic_helper_wait_for_fences(dev, old_state, false);
• mutex_lock(&private->hw_lock);
• 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);
  

• mutex_unlock(&private->hw_lock);

You implement mtk version just want to add mutex protect. But I think you should not protect here because what you should protect is the common variable touched by sync plane and async plane. In mtk_drm_crtc_cursor_update(), you already know what is the variable you need to protect, and these variable is touched in mtk_drm_crtc_atomic_flush() or mtk_plane_atomic_update(), so I think you should just protect inside these function and need not to implement this function.

Regards, CK

• drm_atomic_helper_fake_vblank(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 mtk_drm_mode_config_helpers = {

• .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,

• .atomic_commit_tail = mtk_drm_atomic_helper_commit_tail_rpm,

};

static const struct drm_mode_config_funcs mtk_drm_mode_config_funcs = { @@ -262,6 +281,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)

drm_kms_helper_poll_init(drm); drm_mode_config_reset(drm);

• mutex_init(&private->hw_lock);

  return 0;

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h index 9f4ce60174f6..c61adaa92626 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h @@ -48,6 +48,8 @@ struct mtk_drm_private { const struct mtk_mmsys_driver_data *data; struct drm_atomic_state *suspend_state;

• /* lock for display hw access */
• struct mutex hw_lock; bool dma_parms_allocated;

};

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c index cd7c97eb7ee6..d7a8853d94a1 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c @@ -7,6 +7,7 @@ #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_fourcc.h> +#include <drm/drm_atomic_uapi.h> #include <drm/drm_plane_helper.h> #include <drm/drm_gem_framebuffer_helper.h>

@@ -70,6 +71,50 @@ static void mtk_drm_plane_destroy_state(struct drm_plane *plane, kfree(to_mtk_plane_state(state)); }

+static int mtk_plane_atomic_async_check(struct drm_plane *plane,

• 			struct drm_plane_state *state)
  

+{

• struct drm_crtc_state *crtc_state;
• if (plane != state->crtc->cursor)

• return -EINVAL;
  

• if (!plane->state)

• return -EINVAL;
  

• if (!plane->state->fb)

• return -EINVAL;
  

• if (state->state)

• crtc_state = drm_atomic_get_existing_crtc_state(state->state,
  

• 						state->crtc);
  

• else /* Special case for asynchronous cursor updates. */

• crtc_state = state->crtc->state;
  

• return drm_atomic_helper_check_plane_state(plane->state, crtc_state,

• 				   DRM_PLANE_HELPER_NO_SCALING,
  

• 				   DRM_PLANE_HELPER_NO_SCALING,
  

• 				   true, true);
  

+}

+static void mtk_plane_atomic_async_update(struct drm_plane *plane,

• 			  struct drm_plane_state *new_state)
  

+{

• struct mtk_plane_state *state = to_mtk_plane_state(plane->state);
• plane->state->crtc_x = new_state->crtc_x;
• plane->state->crtc_y = new_state->crtc_y;
• plane->state->crtc_h = new_state->crtc_h;
• plane->state->crtc_w = new_state->crtc_w;
• plane->state->src_x = new_state->src_x;
• plane->state->src_y = new_state->src_y;
• plane->state->src_h = new_state->src_h;
• plane->state->src_w = new_state->src_w;
• state->pending.cursor_update = true;
• mtk_drm_crtc_cursor_update(new_state->crtc, plane, new_state);

+}

static const struct drm_plane_funcs mtk_plane_funcs = { .update_plane = drm_atomic_helper_update_plane, .disable_plane = drm_atomic_helper_disable_plane, @@ -141,6 +186,9 @@ static void mtk_plane_atomic_update(struct drm_plane *plane, state->pending.rotation = plane->state->rotation; wmb(); /* Make sure the above parameters are set before update */ state->pending.dirty = true;

• if (state->pending.cursor_update)

• state->pending.cursor_dirty = true;
  

}

static void mtk_plane_atomic_disable(struct drm_plane *plane, @@ -158,6 +206,8 @@ static const struct drm_plane_helper_funcs mtk_plane_helper_funcs = { .atomic_check = mtk_plane_atomic_check, .atomic_update = mtk_plane_atomic_update, .atomic_disable = mtk_plane_atomic_disable,

• .atomic_async_update = mtk_plane_atomic_async_update,
• .atomic_async_check = mtk_plane_atomic_async_check,

};

int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane, diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.h b/drivers/gpu/drm/mediatek/mtk_drm_plane.h index 760885e35b27..113a10344805 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.h +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.h @@ -22,6 +22,8 @@ struct mtk_plane_pending_state { unsigned int height; unsigned int rotation; bool dirty;

• bool cursor_dirty;
• bool cursor_update;

};

struct mtk_plane_state {