From: Jitao Shi jitao.shi@mediatek.com
DP 1.4a Section 2.8.7.1.5.6.1: A DP Source device shall retry at least seven times upon receiving AUX_DEFER before giving up the AUX transaction.
Aux should retry to send msg whether how many bytes.
Signed-off-by: Jitao Shi jitao.shi@mediatek.com Signed-off-by: Guillaume Ranquet granquet@baylibre.com --- drivers/gpu/drm/mediatek/mtk_dp.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index 4981a3a3b9ca..de2a1c1b4f8c 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -2018,7 +2018,7 @@ static ssize_t mtk_dp_aux_transfer(struct drm_dp_aux *mtk_aux, bool is_read; u8 request; size_t accessed_bytes = 0; - int retry = 3, ret = 0; + int retry, ret = 0;
mtk_dp = container_of(mtk_aux, struct mtk_dp, aux);
@@ -2052,14 +2052,21 @@ static ssize_t mtk_dp_aux_transfer(struct drm_dp_aux *mtk_aux, }
if (msg->size == 0) { - ret = mtk_dp_aux_do_transfer(mtk_dp, is_read, request, - msg->address + accessed_bytes, - msg->buffer + accessed_bytes, 0); + retry = 32; + while (retry--) { + ret = mtk_dp_aux_do_transfer(mtk_dp, is_read, request, + msg->address + accessed_bytes, + msg->buffer + accessed_bytes, 0); + if (ret == 0) + break; + usleep_range(500, 600); + } } else { while (accessed_bytes < msg->size) { size_t to_access = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES, msg->size - accessed_bytes); + retry = 32; while (retry--) { ret = mtk_dp_aux_do_transfer(mtk_dp, is_read, request, @@ -2068,7 +2075,7 @@ static ssize_t mtk_dp_aux_transfer(struct drm_dp_aux *mtk_aux, to_access); if (ret == 0) break; - usleep_range(50, 100); + usleep_range(500, 600); } if (!retry || ret) { drm_info(mtk_dp->drm_dev,