[PATCH v3 1/3] drm/bridge: dw-hdmi: change YUV420 selection logic at clock setup

[Adrián Larumbe]

Right now clocking value selection code is prioritising RGB, YUV444 modes
over YUV420 for HDMI2 sinks. However, because of the bus format selection
procedure in dw-hdmi, for HDMI2 sinks YUV420 is the format that will always
be picked during the drm bridge chain check stage.

Later on dw_hdmi_setup will configure a colour space based on the bus
format that doesn't match the pixel value we had calculated as described
above.

Fix it by bringing back dw-hdmi bus format check when picking the right
pixel clock.

Signed-off-by: Adrián Larumbe <adrian.larumbe at collabora.com>
Acked-by: Neil Armstrong <neil.armstrong at linaro.org>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 6 ++++++
 drivers/gpu/drm/meson/meson_dw_hdmi.c     | 4 ++--
 include/drm/bridge/dw_hdmi.h              | 2 ++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 3b40e0fdca5c..e6a456b72610 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -3346,6 +3346,12 @@ static int dw_hdmi_parse_dt(struct dw_hdmi *hdmi)
 	return 0;
 }
 
+bool dw_hdmi_bus_fmt_is_420(struct dw_hdmi *hdmi)
+{
+	return hdmi_bus_fmt_is_yuv420(hdmi->hdmi_data.enc_out_bus_format);
+}
+EXPORT_SYMBOL_GPL(dw_hdmi_bus_fmt_is_420);
+
 struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
 			      const struct dw_hdmi_plat_data *plat_data)
 {
diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
index 3d046878ce6c..b49bb0d86efe 100644
--- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
+++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
@@ -379,8 +379,8 @@ static int dw_hdmi_phy_init(struct dw_hdmi *hdmi, void *data,
 			 mode->clock > 340000 ? 40 : 10);
 
 	if (drm_mode_is_420_only(display, mode) ||
-	    (!is_hdmi2_sink &&
-	     drm_mode_is_420_also(display, mode)))
+	    (!is_hdmi2_sink && drm_mode_is_420_also(display, mode)) ||
+	    dw_hdmi_bus_fmt_is_420(hdmi))
 		mode_is_420 = true;
 
 	/* Enable clocks */
diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index f668e75fbabe..6a46baa0737c 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -206,4 +206,6 @@ void dw_hdmi_phy_update_hpd(struct dw_hdmi *hdmi, void *data,
 			    bool force, bool disabled, bool rxsense);
 void dw_hdmi_phy_setup_hpd(struct dw_hdmi *hdmi, void *data);
 
+bool dw_hdmi_bus_fmt_is_420(struct dw_hdmi *hdmi);
+
 #endif /* __IMX_HDMI_H__ */
-- 
2.40.0