Commit 98703e4e authored by Adrián Larumbe's avatar Adrián Larumbe Committed by Neil Armstrong
Browse files

drm: bridge: dw_hdmi: fix connector access for scdc 



Commit 5d844091 ("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.

Fixes: 5d844091 ("drm/scdc-helper: Pimp SCDC debugs")
Signed-off-by: default avatarAdrián Larumbe <adrian.larumbe@collabora.com>
Reported-by: default avatarLukas F. Hartmann <lukas@mntre.com>
Acked-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
[narmstrong: moved Fixes tag before first S-o-b and added Reported-by tag]
Signed-off-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230601123153.196867-1-adrian.larumbe@collabora.com
parent e30cb059

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

+5 −4
Original line number Diff line number Diff line
@@ -1426,9 +1426,9 @@ 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);
@@ -2116,7 +2116,7 @@ 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
@@ -2132,7 +2132,7 @@ 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);

		}

	}
@@ -3553,6 +3553,7 @@ 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;

#ifdef CONFIG_OF

	hdmi->bridge.of_node = pdev->dev.of_node;

#endif