Hi !

On 01/06/2023 14:31, Adrián Larumbe wrote:
Commit 5d844091f237 ("drm/scdc-helper: Pimp SCDC debugs") changed the scdc
interface to pick up an i2c adapter from a connector instead. However, in
the case of dw-hdmi, the wrong connector was being used to pass i2c adapter
information, since dw-hdmi's embedded connector structure is only populated
when the bridge attachment callback explicitly asks for it.

drm-meson is handling connector creation, so this won't happen, leading to
a NULL pointer dereference.

Fix it by having scdc functions access dw-hdmi's current connector pointer
instead, which is assigned during the bridge enablement stage.

Signed-off-by: Adrián Larumbe <[email protected]>
Fixes: 5d844091f237 ("drm/scdc-helper: Pimp SCDC debugs")

Fixes should go first.

I missed again this change because you again used my old baylibre address,
but git-send-email should not use it anymore since a .mailmap entry exists
upstream since september 2022.

Anyway, please use get_maintainers on the current working tree or use b4 to
get the most recent maintainers, reviewers & list emails.

---
  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 9 +++++----
  1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c 
b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 0accfb51509c..69c0e80b8525 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -1412,9 +1412,9 @@ void dw_hdmi_set_high_tmds_clock_ratio(struct dw_hdmi 
*hdmi,
        /* Control for TMDS Bit Period/TMDS Clock-Period Ratio */
        if (dw_hdmi_support_scdc(hdmi, display)) {
                if (mtmdsclock > HDMI14_MAX_TMDSCLK)
-                       drm_scdc_set_high_tmds_clock_ratio(&hdmi->connector, 1);
+                       drm_scdc_set_high_tmds_clock_ratio(hdmi->curr_conn, 1);
                else
-                       drm_scdc_set_high_tmds_clock_ratio(&hdmi->connector, 0);
+                       drm_scdc_set_high_tmds_clock_ratio(hdmi->curr_conn, 0);
        }
  }
  EXPORT_SYMBOL_GPL(dw_hdmi_set_high_tmds_clock_ratio);
@@ -2102,7 +2102,7 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi,
                                min_t(u8, bytes, SCDC_MIN_SOURCE_VERSION));
/* Enabled Scrambling in the Sink */
-                       drm_scdc_set_scrambling(&hdmi->connector, 1);
+                       drm_scdc_set_scrambling(hdmi->curr_conn, 1);
/*
                         * To activate the scrambler feature, you must ensure
@@ -2118,7 +2118,7 @@ static void hdmi_av_composer(struct dw_hdmi *hdmi,
                        hdmi_writeb(hdmi, 0, HDMI_FC_SCRAMBLER_CTRL);
                        hdmi_writeb(hdmi, (u8)~HDMI_MC_SWRSTZ_TMDSSWRST_REQ,
                                    HDMI_MC_SWRSTZ);
-                       drm_scdc_set_scrambling(&hdmi->connector, 0);
+                       drm_scdc_set_scrambling(hdmi->curr_conn, 0);
                }
        }
@@ -3546,6 +3546,7 @@ struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
        hdmi->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID
                         | DRM_BRIDGE_OP_HPD;
        hdmi->bridge.interlace_allowed = true;
+       hdmi->bridge.ddc = hdmi->ddc;

I missed this one on my change...

  #ifdef CONFIG_OF
        hdmi->bridge.of_node = pdev->dev.of_node;
  #endif

I'll add:
Reported-by: Lukas F. Hartmann <[email protected]>

while applying and:

Acked-by: Neil Armstrong <[email protected]>

Thanks,
Neil

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