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

[Paul Cercueil <paul@xxxxxxxxxxxxxxx>]

Hi Daniel,

Le mar., juin 1 2021 at 17:48:12 +0200, Daniel Vetter <daniel@xxxxxxxx> 
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 <paul@xxxxxxxxxxxxxxx>
>
> 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