[PATCH] drm/connector: Allow clearing HDMI infoframes

[Derek Foreman]

Our infoframe setting code currently lacks the ability to clear
infoframes. For some of the infoframes, we only need to replace them,
so if an error occurred when generating a new infoframe we would leave
a stale frame instead of clearing the frame.

However, the Dynamic Range and Mastering (DRM) infoframe should only
be present when displaying HDR content (ie: the HDR_OUTPUT_METADATA blob
is set). If we can't clear infoframes, the stale DRM infoframe will
remain and we can never set the display back to SDR mode.

With this change, we clear infoframes when they can not, or should not,
be generated. This fixes switching to an SDR mode from an HDR one.

Fixes: f378b77227bc4 ("drm/connector: hdmi: Add Infoframes generation")
Signed-off-by: Derek Foreman <derek.foreman at collabora.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index feb7a3a75981..936a8f95d80f 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -347,6 +347,8 @@ static int hdmi_generate_avi_infoframe(const struct drm_connector *connector,
 		is_limited_range ? HDMI_QUANTIZATION_RANGE_LIMITED : HDMI_QUANTIZATION_RANGE_FULL;
 	int ret;
 
+	infoframe->set = false;
+
 	ret = drm_hdmi_avi_infoframe_from_display_mode(frame, connector, mode);
 	if (ret)
 		return ret;
@@ -376,6 +378,8 @@ static int hdmi_generate_spd_infoframe(const struct drm_connector *connector,
 		&infoframe->data.spd;
 	int ret;
 
+	infoframe->set = false;
+
 	ret = hdmi_spd_infoframe_init(frame,
 				      connector->hdmi.vendor,
 				      connector->hdmi.product);
@@ -398,6 +402,8 @@ static int hdmi_generate_hdr_infoframe(const struct drm_connector *connector,
 		&infoframe->data.drm;
 	int ret;
 
+	infoframe->set = false;
+
 	if (connector->max_bpc < 10)
 		return 0;
 
@@ -425,6 +431,8 @@ static int hdmi_generate_hdmi_vendor_infoframe(const struct drm_connector *conne
 		&infoframe->data.vendor.hdmi;
 	int ret;
 
+	infoframe->set = false;
+
 	if (!info->has_hdmi_infoframe)
 		return 0;
 
-- 
2.45.2