[PATCH v2 7/7] drm: rcar-du: Stop accessing non-existant registers on gen4

[Laurent Pinchart]

On Fri, Jan 20, 2023 at 10:50:09AM +0200, Tomi Valkeinen wrote:
> The following registers do not exist on gen4, so we should not write
> them: DEF6Rm, DEF7Rm, DEF8Rm, ESCRn, OTARn.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas at ideasonboard.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
> ---
>  drivers/gpu/drm/rcar-du/rcar_du_crtc.c  |  8 +++++---
>  drivers/gpu/drm/rcar-du/rcar_du_group.c | 11 ++++++++---
>  2 files changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> index b7dd59fe119e..008e172ed43b 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> @@ -298,10 +298,12 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc)
>  		escr = params.escr;
>  	}
>  
> -	dev_dbg(rcrtc->dev->dev, "%s: ESCR 0x%08x\n", __func__, escr);
> +	if (rcdu->info->gen < 4) {
> +		dev_dbg(rcrtc->dev->dev, "%s: ESCR 0x%08x\n", __func__, escr);
>  
> -	rcar_du_crtc_write(rcrtc, rcrtc->index % 2 ? ESCR13 : ESCR02, escr);
> -	rcar_du_crtc_write(rcrtc, rcrtc->index % 2 ? OTAR13 : OTAR02, 0);
> +		rcar_du_crtc_write(rcrtc, rcrtc->index % 2 ? ESCR13 : ESCR02, escr);
> +		rcar_du_crtc_write(rcrtc, rcrtc->index % 2 ? OTAR13 : OTAR02, 0);
> +	}
>  
>  	/* Signal polarities */
>  	dsmr = ((mode->flags & DRM_MODE_FLAG_PVSYNC) ? DSMR_VSL : 0)
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_group.c b/drivers/gpu/drm/rcar-du/rcar_du_group.c
> index 6da01760ede5..c2209d427bb7 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_group.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_group.c
> @@ -148,7 +148,8 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
>  	}
>  	rcar_du_group_write(rgrp, DEFR5, DEFR5_CODE | DEFR5_DEFE5);
>  
> -	rcar_du_group_setup_pins(rgrp);
> +	if (rcdu->info->gen < 4)
> +		rcar_du_group_setup_pins(rgrp);
>  
>  	/*
>  	 * TODO: Handle routing of the DU output to CMM dynamically, as we
> @@ -160,7 +161,8 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
>  	rcar_du_group_write(rgrp, DEFR7, defr7);
>  
>  	if (rcdu->info->gen >= 2) {
> -		rcar_du_group_setup_defr8(rgrp);
> +		if (rcdu->info->gen < 4)
> +			rcar_du_group_setup_defr8(rgrp);
>  		rcar_du_group_setup_didsr(rgrp);
>  	}
>  
> @@ -192,10 +194,13 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
>   */
>  int rcar_du_group_get(struct rcar_du_group *rgrp)
>  {
> +	struct rcar_du_device *rcdu = rgrp->dev;
> +
>  	if (rgrp->use_count)
>  		goto done;
>  
> -	rcar_du_group_setup(rgrp);
> +	if (rcdu->info->gen < 4)
> +		rcar_du_group_setup(rgrp);

This doesn't look right, you're disabling way more than necessary.

>  
>  done:
>  	rgrp->use_count++;

-- 
Regards,

Laurent Pinchart