Re: [PATCH 1/3] drm/ingenic: ipu: Only restart manually on older SoCs

[Sam Ravnborg]

On Thu, Jul 30, 2020 at 03:46:24AM +0200, Paul Cercueil wrote:
> On older SoCs, it is necessary to restart manually the IPU when a frame
> is done processing. Doing so on newer SoCs (JZ4760/70) kinds of work
> too, until the input or output resolutions or the framerate are too
> high.
> 
> Make it work properly on newer SoCs by letting the LCD controller
> trigger the IPU frame restart signal.
> 
> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Reviewed-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/ingenic/ingenic-ipu.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ingenic/ingenic-ipu.c b/drivers/gpu/drm/ingenic/ingenic-ipu.c
> index 7a0a8bd865d3..7eae56fa92ea 100644
> --- a/drivers/gpu/drm/ingenic/ingenic-ipu.c
> +++ b/drivers/gpu/drm/ingenic/ingenic-ipu.c
> @@ -35,6 +35,7 @@ struct soc_info {
>  	const u32 *formats;
>  	size_t num_formats;
>  	bool has_bicubic;
> +	bool manual_restart;
>  
>  	void (*set_coefs)(struct ingenic_ipu *ipu, unsigned int reg,
>  			  unsigned int sharpness, bool downscale,
> @@ -645,7 +646,8 @@ static irqreturn_t ingenic_ipu_irq_handler(int irq, void *arg)
>  	unsigned int dummy;
>  
>  	/* dummy read allows CPU to reconfigure IPU */
> -	regmap_read(ipu->map, JZ_REG_IPU_STATUS, &dummy);
> +	if (ipu->soc_info->manual_restart)
> +		regmap_read(ipu->map, JZ_REG_IPU_STATUS, &dummy);
>  
>  	/* ACK interrupt */
>  	regmap_write(ipu->map, JZ_REG_IPU_STATUS, 0);
> @@ -656,7 +658,8 @@ static irqreturn_t ingenic_ipu_irq_handler(int irq, void *arg)
>  	regmap_write(ipu->map, JZ_REG_IPU_V_ADDR, ipu->addr_v);
>  
>  	/* Run IPU for the new frame */
> -	regmap_set_bits(ipu->map, JZ_REG_IPU_CTRL, JZ_IPU_CTRL_RUN);
> +	if (ipu->soc_info->manual_restart)
> +		regmap_set_bits(ipu->map, JZ_REG_IPU_CTRL, JZ_IPU_CTRL_RUN);
>  
>  	drm_crtc_handle_vblank(crtc);
>  
> @@ -806,6 +809,7 @@ static const struct soc_info jz4725b_soc_info = {
>  	.formats	= jz4725b_ipu_formats,
>  	.num_formats	= ARRAY_SIZE(jz4725b_ipu_formats),
>  	.has_bicubic	= false,
> +	.manual_restart	= true,
>  	.set_coefs	= jz4725b_set_coefs,
>  };
>  
> @@ -831,6 +835,7 @@ static const struct soc_info jz4760_soc_info = {
>  	.formats	= jz4760_ipu_formats,
>  	.num_formats	= ARRAY_SIZE(jz4760_ipu_formats),
>  	.has_bicubic	= true,
> +	.manual_restart	= false,
>  	.set_coefs	= jz4760_set_coefs,
>  };
>  
> -- 
> 2.27.0