[PATCH v3 08/10] drm/display: hdmi_state_helper: don't generate unsupported InfoFrames

[Dmitry Baryshkov]

There is little point in generating InfoFrames which are not supported
by the driver. Skip generating the unsupported InfoFrames, making sure
that the kernel never tries to write the unsupported frame. As there are
no remaining usecases, change write_infoframe / clear_infoframe helpers
return an error if the corresponding callback is NULL.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at oss.qualcomm.com>
---
 drivers/gpu/drm/display/drm_hdmi_state_helper.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
index e8556bf9e1da..a1d16762ac7a 100644
--- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c
@@ -718,6 +718,9 @@ static int hdmi_generate_spd_infoframe(const struct drm_connector *connector,
 
 	infoframe->set = false;
 
+	if (!connector->hdmi.funcs->spd.write_infoframe)
+		return 0;
+
 	ret = hdmi_spd_infoframe_init(frame,
 				      connector->hdmi.vendor,
 				      connector->hdmi.product);
@@ -742,6 +745,9 @@ static int hdmi_generate_hdr_infoframe(const struct drm_connector *connector,
 
 	infoframe->set = false;
 
+	if (!connector->hdmi.funcs->hdr_drm.write_infoframe)
+		return 0;
+
 	if (connector->max_bpc < 10)
 		return 0;
 
@@ -902,7 +908,7 @@ static int clear_infoframe(struct drm_connector *connector,
 
 	if (!funcs->clear_infoframe) {
 		drm_dbg_kms(dev, "Function not implemented, bailing.\n");
-		return 0;
+		return -EOPNOTSUPP;
 	}
 
 	ret = funcs->clear_infoframe(connector);
@@ -928,7 +934,7 @@ static int write_infoframe(struct drm_connector *connector,
 
 	if (!funcs->write_infoframe) {
 		drm_dbg_kms(dev, "Function not implemented, bailing.\n");
-		return 0; /* XXX: temporal until we stop generating unsupported frames */
+		return -EOPNOTSUPP;
 	}
 
 	len = hdmi_infoframe_pack(&new_frame->data, buffer, sizeof(buffer));

-- 
2.47.3