* [PATCH v1 1/1] drm/mediatek: Add return value check when reading DPCD
@ 2024-09-30 9:17 Liankun Yang
2024-10-22 10:05 ` CK Hu (胡俊光)
0 siblings, 1 reply; 2+ messages in thread
From: Liankun Yang @ 2024-09-30 9:17 UTC (permalink / raw)
To: chunkuang.hu, p.zabel, airlied, simona, matthias.bgg,
angelogioacchino.delregno, msp, rex-bc.chen, dmitry.osipenko,
ck.hu, jitao.shi, mac.shen, peng.liu, liankun.yang
Cc: Project_Global_Chrome_Upstream_Group, dri-devel, linux-mediatek,
linux-kernel, linux-arm-kernel
Returns the number of bytes transferred (1) on success.
Check the return value to confirm that AUX communication is successful.
Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Liankun Yang <liankun.yang@mediatek.com>
---
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 d8796a904eca..3cab65345d1e 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -2018,6 +2018,7 @@ 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;
@@ -2032,7 +2033,12 @@ 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;
--
2.45.2
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [PATCH v1 1/1] drm/mediatek: Add return value check when reading DPCD
2024-09-30 9:17 [PATCH v1 1/1] drm/mediatek: Add return value check when reading DPCD Liankun Yang
@ 2024-10-22 10:05 ` CK Hu (胡俊光)
0 siblings, 0 replies; 2+ messages in thread
From: CK Hu (胡俊光) @ 2024-10-22 10:05 UTC (permalink / raw)
To: Peng Liu (刘鹏), Mac Shen (沈俊),
chunkuang.hu, simona, Jitao Shi (石记涛),
LIANKUN YANG (杨连坤),
p.zabel, airlied, msp, matthias.bgg, dmitry.osipenko,
Rex-BC Chen (陳柏辰),
AngeloGioacchino Del Regno
Cc: dri-devel, linux-kernel, linux-mediatek, linux-arm-kernel,
Project_Global_Chrome_Upstream_Group
Hi, Liankun:
On Mon, 2024-09-30 at 17:17 +0800, Liankun Yang wrote:
> Returns the number of bytes transferred (1) on success.
> Check the return value to confirm that AUX communication is successful.
>
> Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Fixes: d9e6ea02fc3f ("drm/mediatek: dp: Add MT8195 External DisplayPort support")
Regards,
CK
>
> Signed-off-by: Liankun Yang <liankun.yang@mediatek.com>
> ---
> 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 d8796a904eca..3cab65345d1e 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dp.c
> @@ -2018,6 +2018,7 @@ 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;
> @@ -2032,7 +2033,12 @@ 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;
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2024-09-30 9:17 [PATCH v1 1/1] drm/mediatek: Add return value check when reading DPCD Liankun Yang
2024-10-22 10:05 ` CK Hu (胡俊光)
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