drm/mediatek: dp: Fix mtk_dp_aux_transfer return value
authorWojciech Macek <wmacek@chromium.org>
Wed, 17 Apr 2024 10:38:19 +0000 (10:38 +0000)
committerChun-Kuang Hu <chunkuang.hu@kernel.org>
Mon, 22 Apr 2024 13:29:07 +0000 (13:29 +0000)
commit8431fff9e0f3fc1c5844cf99a73b49b63ceed481
tree7e28db57e070db87bd55f414b2dded7abbd3bcb5
parent499eb5197d86f54a68ced91725cd7efa1e397c01
drm/mediatek: dp: Fix mtk_dp_aux_transfer return value

In case there is no DP device attached to the port the
transfer function should return IO error, similar to what
other drivers do.
In case EAGAIN is returned then any read from /dev/drm_dp_aux
device ends up in an infinite loop as the upper layers
constantly repeats the transfer request.

Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Wojciech Macek <wmacek@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240417103819.990512-1-wmacek@chromium.org/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
drivers/gpu/drm/mediatek/mtk_dp.c