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

[Tomi Valkeinen]

On 20/01/2023 18:21, Laurent Pinchart wrote:
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+rene...@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+rene...@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.

You're right, doesn't look even remotely correct. A morning patch, 
obviously.

 Tomi