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 | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c index fe91ab8b2fd89..4e880d8a8a186 100644 --- a/drivers/gpu/drm/mediatek/mtk_dp.c +++ b/drivers/gpu/drm/mediatek/mtk_dp.c @@ -1879,7 +1879,7 @@ 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);
@@ -1913,15 +1913,21 @@ 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 = 7; + 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; + msleep(50); } } else { while (accessed_bytes < msg->size) { size_t to_access = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES, msg->size - accessed_bytes); + retry = 7; while (retry--) { ret = mtk_dp_aux_do_transfer(mtk_dp, is_read, request,