Re: [PATCH 04/11] drm/ingenic: Move no_vblank to private state

[Paul Cercueil]

Hi Daniel,

Le mar., juin 1 2021 at 17:48:12 +0200, Daniel Vetter <dan...@ffwll.ch> 
a écrit :
On Fri, May 28, 2021 at 12:20:58AM +0100, Paul Cercueil wrote:
 This information is carried from the ".atomic_check" to the
 ".atomic_commit_tail"; as such it is state-specific, and should be 
moved
 to the private state structure.
 Signed-off-by: Paul Cercueil <p...@crapouillou.net>

Not sure this applies to your hw, but drm_crtc_state.no_vblank exists.
Might want to move to that instead of rolling your own. Or explain 
why you
need your own here in your own private state. It does look quite a bit
like you're just rolling your own version of this support that helpers
gained meanwhile.

If I use drm_crtc_state->no_vblank, then I need a custom 
.atomic_commit_tail() that only calls 
drm_atomic_helper_wait_for_vblanks() when !no_vblank. That works, but I 
don't understand why drm_atomic_helper_commit_tail() doesn't do that by 
default, and makes me think I'm using it wrong.

Cheers,
-Paul

-Daniel


 ---
  drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 41 
++++++++++++++++++++---
  1 file changed, 37 insertions(+), 4 deletions(-)

 diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c 
b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
 index e81084eb3b0e..639994329c60 100644
 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
 +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
 @@ -66,6 +66,8 @@ struct jz_soc_info {

  struct ingenic_drm_private_state {
        struct drm_private_state base;
 +
 +      bool no_vblank;
  };

  struct ingenic_drm {
 @@ -87,7 +89,6 @@ struct ingenic_drm {
        dma_addr_t dma_hwdescs_phys;

        bool panel_is_sharp;
 -      bool no_vblank;

        /*
  	 * clk_mutex is used to synchronize the pixel clock rate update 
with
 @@ -113,6 +114,30 @@ to_ingenic_drm_priv_state(struct 
drm_private_state *state)
  	return container_of(state, struct ingenic_drm_private_state, 
base);
  }

 +static struct ingenic_drm_private_state *
 +ingenic_drm_get_priv_state(struct ingenic_drm *priv, struct 
drm_atomic_state *state)
 +{
 +      struct drm_private_state *priv_state;
 +
 +	priv_state = drm_atomic_get_private_obj_state(state, 
&priv->private_obj);
 +      if (IS_ERR(priv_state))
 +              return ERR_CAST(priv_state);
 +
 +      return to_ingenic_drm_priv_state(priv_state);
 +}
 +
 +static struct ingenic_drm_private_state *
 +ingenic_drm_get_new_priv_state(struct ingenic_drm *priv, struct 
drm_atomic_state *state)
 +{
 +      struct drm_private_state *priv_state;
 +
 +	priv_state = drm_atomic_get_new_private_obj_state(state, 
&priv->private_obj);
 +      if (!priv_state)
 +              return NULL;
 +
 +      return to_ingenic_drm_priv_state(priv_state);
 +}
 +
  static bool ingenic_drm_writeable_reg(struct device *dev, unsigned 
int reg)
  {
        switch (reg) {
 @@ -268,6 +293,7 @@ static int ingenic_drm_crtc_atomic_check(struct 
drm_crtc *crtc,
                                                                          crtc);
        struct ingenic_drm *priv = drm_crtc_get_priv(crtc);
        struct drm_plane_state *f1_state, *f0_state, *ipu_state = NULL;
 +      struct ingenic_drm_private_state *priv_state;

        if (crtc_state->gamma_lut &&
  	    drm_color_lut_size(crtc_state->gamma_lut) != 
ARRAY_SIZE(priv->dma_hwdescs->palette)) {
 @@ -299,9 +325,13 @@ static int 
ingenic_drm_crtc_atomic_check(struct drm_crtc *crtc,
                        }
                }

 +              priv_state = ingenic_drm_get_priv_state(priv, state);
 +              if (IS_ERR(priv_state))
 +                      return PTR_ERR(priv_state);
 +
                /* If all the planes are disabled, we won't get a VBLANK IRQ */
 -              priv->no_vblank = !f1_state->fb && !f0_state->fb &&
 -                                !(ipu_state && ipu_state->fb);
 +              priv_state->no_vblank = !f1_state->fb && !f0_state->fb &&
 +                                      !(ipu_state && ipu_state->fb);
        }

        return 0;
 @@ -727,6 +757,7 @@ static void 
ingenic_drm_atomic_helper_commit_tail(struct drm_atomic_state *old_s
         */
        struct drm_device *dev = old_state->dev;
        struct ingenic_drm *priv = drm_device_get_priv(dev);
 +      struct ingenic_drm_private_state *priv_state;

        drm_atomic_helper_commit_modeset_disables(dev, old_state);

 @@ -736,7 +767,9 @@ static void 
ingenic_drm_atomic_helper_commit_tail(struct drm_atomic_state *old_s

        drm_atomic_helper_commit_hw_done(old_state);

 -      if (!priv->no_vblank)
 +      priv_state = ingenic_drm_get_new_priv_state(priv, old_state);
 +
 +      if (!priv_state || !priv_state->no_vblank)
                drm_atomic_helper_wait_for_vblanks(dev, old_state);

        drm_atomic_helper_cleanup_planes(dev, old_state);
 --
 2.30.2


--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch