Re: [PATCH v3 6/6] drm: arc: Use crtc->mode_valid() callback

[Daniel Vetter]

On Thu, May 11, 2017 at 10:06:02AM +0100, Jose Abreu wrote:
> Now that we have a callback to check if crtc supports a given mode
> we can use it in arcpgu so that we restrict the number of probbed
> modes to the ones we can actually display.
> 
> This is specially useful because arcpgu crtc is responsible to set
> a clock value in the commit() stage but unfortunatelly this clock
> does not support all the needed ranges.
> 
> Also, remove the atomic_check() callback as mode_valid() callback
> will be called before.
> 
> Signed-off-by: Jose Abreu <joabreu@xxxxxxxxxxxx>
> Cc: Carlos Palminha <palminha@xxxxxxxxxxxx>
> Cc: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> Cc: Dave Airlie <airlied@xxxxxxxx>
> Cc: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>

Btw for justifying your patch series a bit more, would be real sweet to
roll ->mode_valid out to more drivers. I see two easy cases:

bridge/analogix-anx78xx.c: has a simple mode_fixup which really is just a
mode_valid callback

bridge/synopsys/dw-hdmi.c: simply hand-rolls what you've done here, we
could move the connector_mode valid to the bridge and done.

Care to type these 2 patches on top, just to make this a bit more useful
and a clearer case for merging?

Thanks, Daniel

> ---
>  drivers/gpu/drm/arc/arcpgu_crtc.c | 39 ++++++++++++++++++++++++---------------
>  1 file changed, 24 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c b/drivers/gpu/drm/arc/arcpgu_crtc.c
> index ad9a959..01cae0a 100644
> --- a/drivers/gpu/drm/arc/arcpgu_crtc.c
> +++ b/drivers/gpu/drm/arc/arcpgu_crtc.c
> @@ -32,6 +32,18 @@
>  	{ "r8g8b8", 24, {16, 8}, {8, 8}, {0, 8}, {0, 0}, DRM_FORMAT_RGB888 },
>  };
>  
> +static bool arc_pgu_is_mode_valid(struct arcpgu_drm_private *arcpgu,
> +				  const struct drm_display_mode *mode)
> +{
> +	long rate, clk_rate = mode->clock * 1000;
> +
> +	rate = clk_round_rate(arcpgu->clk, clk_rate);
> +	if (rate != clk_rate)
> +		return false;
> +
> +	return true;
> +}
> +
>  static void arc_pgu_set_pxl_fmt(struct drm_crtc *crtc)
>  {
>  	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
> @@ -64,6 +76,17 @@ static void arc_pgu_set_pxl_fmt(struct drm_crtc *crtc)
>  	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
>  };
>  
> +enum drm_mode_status arc_pgu_crtc_mode_valid(struct drm_crtc *crtc,
> +					     const struct drm_display_mode *mode)
> +{
> +	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
> +
> +	if (!arc_pgu_is_mode_valid(arcpgu, mode))
> +		return MODE_NOCLOCK;
> +
> +	return MODE_OK;
> +}
> +
>  static void arc_pgu_crtc_mode_set_nofb(struct drm_crtc *crtc)
>  {
>  	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
> @@ -129,20 +152,6 @@ static void arc_pgu_crtc_disable(struct drm_crtc *crtc)
>  			      ~ARCPGU_CTRL_ENABLE_MASK);
>  }
>  
> -static int arc_pgu_crtc_atomic_check(struct drm_crtc *crtc,
> -				     struct drm_crtc_state *state)
> -{
> -	struct arcpgu_drm_private *arcpgu = crtc_to_arcpgu_priv(crtc);
> -	struct drm_display_mode *mode = &state->adjusted_mode;
> -	long rate, clk_rate = mode->clock * 1000;
> -
> -	rate = clk_round_rate(arcpgu->clk, clk_rate);
> -	if (rate != clk_rate)
> -		return -EINVAL;
> -
> -	return 0;
> -}
> -
>  static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
>  				      struct drm_crtc_state *state)
>  {
> @@ -158,6 +167,7 @@ static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
>  }
>  
>  static const struct drm_crtc_helper_funcs arc_pgu_crtc_helper_funcs = {
> +	.mode_valid	= arc_pgu_crtc_mode_valid,
>  	.mode_set	= drm_helper_crtc_mode_set,
>  	.mode_set_base	= drm_helper_crtc_mode_set_base,
>  	.mode_set_nofb	= arc_pgu_crtc_mode_set_nofb,
> @@ -165,7 +175,6 @@ static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
>  	.disable	= arc_pgu_crtc_disable,
>  	.prepare	= arc_pgu_crtc_disable,
>  	.commit		= arc_pgu_crtc_enable,
> -	.atomic_check	= arc_pgu_crtc_atomic_check,
>  	.atomic_begin	= arc_pgu_crtc_atomic_begin,
>  };
>  
> -- 
> 1.9.1
> 
> 

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