6.4-stable review patch. If anyone has any objections, please let me know.
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From: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com
[ 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@collabora.com Tested-by: Chen-Yu Tsai wenst@chromium.org Reviewed-by: Alexandre Mergnat amergnat@baylibre.com Reviewed-by: CK Hu ck.hu@mediatek.com Link: https://patchwork.kernel.org/project/dri-devel/patch/20230725073234.55892-2-... Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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;