On Thu, 24 Feb 2022 at 23:13, Abhinav Kumar quic_abhinavk@quicinc.com wrote:
On 2/11/2022 2:40 PM, Dmitry Baryshkov wrote:
It is possible to supply display-connector (bridge) to the DP interface, add support for parsing it too.
Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org
drivers/gpu/drm/msm/dp/dp_parser.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c index 901d7967370f..1056b8d5755b 100644 --- a/drivers/gpu/drm/msm/dp/dp_parser.c +++ b/drivers/gpu/drm/msm/dp/dp_parser.c @@ -301,17 +301,22 @@ static int dp_parser_parse(struct dp_parser *parser, int connector_type) return rc;
/*
* Currently we support external bridges only for eDP connectors.
* External bridges are mandatory for eDP interfaces: one has to* provide at least an eDP panel (which gets wrapped into panel-bridge). *
* No external bridges are expected for the DisplayPort connector,* it is physically present in a form of a DP or USB-C connector.
* For DisplayPort interfaces external bridges are optional, so* silently ignore an error if one is not present (-ENODEV). */
if (connector_type == DRM_MODE_CONNECTOR_eDP) {rc = dp_parser_find_next_bridge(parser);if (rc) {DRM_ERROR("DP: failed to find next bridge\n");
rc = dp_parser_find_next_bridge(parser);if (rc == -ENODEV) {if (connector_type == DRM_MODE_CONNECTOR_eDP) {DRM_ERROR("eDP: next bridge is not present\n"); return rc; }} else if (rc) {if (rc != -EPROBE_DEFER)DRM_ERROR("DP: error parsing next bridge: %d\n", rc);return rc; }How is this silently ignoring?
static int dp_display_bind(struct device *dev, struct device *master, void *data) { int rc = 0; struct dp_display_private *dp = dev_get_dp_display_private(dev); struct msm_drm_private *priv = dev_get_drvdata(master); struct drm_device *drm = priv->dev;
dp->dp_display.drm_dev = drm; priv->dp[dp->id] = &dp->dp_display; rc = dp->parser->parse(dp->parser, dp->dp_display.connector_type); if (rc) { DRM_ERROR("device tree parsing failed\n"); goto end; }dp_display_bind will still fail if a bridge is not found.
If supplying a bridge is optional even this should succeed right?
It will succeed as dp_parser_parse() will not return -ENODEV if the connector is not eDP. To rephrase the comment: For the dp_parser_find_next_bridge() result: - for eDP the driver passes all errors to the calling function. - for DP the driver ignores -ENODEV (no external bridge is supplied), but passes all other errors (which can mean e.g. that the bridge is not properly declared or that it did hasn't been probed yet).