6.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
[ Upstream commit cfc146137a9f12e883ba64bc496b6da4d23f26d5 ]
If reading the RX capabilities fails the training pattern will be set
wrongly: add error checking for drm_dp_read_dpcd_caps() and return if
anything went wrong with it.
While at it, also add a less critical error check when writing to
clear the ESI0 IRQ vector.
Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Tested-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
Reviewed-by: CK Hu <ck.hu@xxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230725073234.55892-2-angelogioacchino.delregno@xxxxxxxxxxxxx/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 64eee77452c04..c58b775877a31 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -1588,7 +1588,9 @@ static int mtk_dp_parse_capabilities(struct mtk_dp *mtk_dp)
u8 val;
ssize_t ret;
- drm_dp_read_dpcd_caps(&mtk_dp->aux, mtk_dp->rx_cap);
+ ret = drm_dp_read_dpcd_caps(&mtk_dp->aux, mtk_dp->rx_cap);
+ if (ret < 0)
+ return ret;
if (drm_dp_tps4_supported(mtk_dp->rx_cap))
mtk_dp->train_info.channel_eq_pattern = DP_TRAINING_PATTERN_4;
@@ -1615,10 +1617,13 @@ static int mtk_dp_parse_capabilities(struct mtk_dp *mtk_dp)
return ret == 0 ? -EIO : ret;
}
- if (val)
- drm_dp_dpcd_writeb(&mtk_dp->aux,
- DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0,
- val);
+ if (val) {
+ ret = drm_dp_dpcd_writeb(&mtk_dp->aux,
+ DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0,
+ val);
+ if (ret < 0)
+ return ret;
+ }
}
return 0;
--
2.40.1
