On Thu, 28 Nov 2024 04:08, Liankun Yang <liankun.yang@xxxxxxxxxxxx> wrote:
>Returns the number of bytes transferred (1) on success.
>Check the return value to confirm that AUX communication is successful.
>
>Fixes: d9e6ea02fc3f ("drm/mediatek: dp: Add MT8195 External DisplayPort support")
>
>Signed-off-by: Liankun Yang <liankun.yang@xxxxxxxxxxxx>
>---
>Changes in V2:
>- Modify Fixes in Commit Message.
>Per suggestion from the previous thread:
>https://patchwork.kernel.org/project/linux-mediatek/patch/20240930092000.5385-1-liankun.yang@xxxxxxxxxxxx/
>---
> drivers/gpu/drm/mediatek/mtk_dp.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
>index 1cc916b16471..9dc68ec2ff43 100644
>--- a/drivers/gpu/drm/mediatek/mtk_dp.c
>+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
>@@ -2101,6 +2101,7 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge)
> enum drm_connector_status ret = connector_status_disconnected;
> bool enabled = mtk_dp->enabled;
> u8 sink_count = 0;
>+ size_t value;
>
> if (!mtk_dp->train_info.cable_plugged_in)
> return ret;
>@@ -2115,7 +2116,12 @@ static enum drm_connector_status mtk_dp_bdg_detect(struct drm_bridge *bridge)
> * function, we just need to check the HPD connection to check
> * whether we connect to a sink device.
> */
>- drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count);
>+ value = drm_dp_dpcd_readb(&mtk_dp->aux, DP_SINK_COUNT, &sink_count);
>+ if (value < 0) {
>+ drm_err(mtk_dp->drm_dev, "Failed to read DP Sink Count: %zd\n", value);
>+ return ret;
>+ }
>+
> if (DP_GET_SINK_COUNT(sink_count))
> ret = connector_status_connected;
Hi Liankun,
thx for your fix.
I think your patch could be improved by using the drm_dp_helper
function drm_dp_read_sink_count() ?
Thx,
Guillaume.
>
>--
>2.45.2
