From: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx>
[ Upstream commit 9243d70e05c5989f84f840612965f96b524da925 ]
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.
The drm_dp_i2c_do_msg() function in the drm_dp_helper.c file will
judge the status of the msg->reply parameter passed to aux_transfer
for different processing.
Fixes: f70ac097a2cf ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: Xinlei Lee <xinlei.lee@xxxxxxxxxxxx>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/1680072203-10394-1-git-send-email-xinlei.lee@xxxxxxxxxxxx/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index d28326350ea93..007af69e5026f 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -806,10 +806,9 @@ static int mtk_dp_aux_wait_for_completion(struct mtk_dp *mtk_dp, bool is_read)
}
static int mtk_dp_aux_do_transfer(struct mtk_dp *mtk_dp, bool is_read, u8 cmd,
- u32 addr, u8 *buf, size_t length)
+ u32 addr, u8 *buf, size_t length, u8 *reply_cmd)
{
int ret;
- u32 reply_cmd;
if (is_read && (length > DP_AUX_MAX_PAYLOAD_BYTES ||
(cmd == DP_AUX_NATIVE_READ && !length)))
@@ -841,10 +840,10 @@ static int mtk_dp_aux_do_transfer(struct mtk_dp *mtk_dp, bool is_read, u8 cmd,
/* Wait for feedback from sink device. */
ret = mtk_dp_aux_wait_for_completion(mtk_dp, is_read);
- reply_cmd = mtk_dp_read(mtk_dp, MTK_DP_AUX_P0_3624) &
- AUX_RX_REPLY_COMMAND_AUX_TX_P0_MASK;
+ *reply_cmd = mtk_dp_read(mtk_dp, MTK_DP_AUX_P0_3624) &
+ AUX_RX_REPLY_COMMAND_AUX_TX_P0_MASK;
- if (ret || reply_cmd) {
+ if (ret) {
u32 phy_status = mtk_dp_read(mtk_dp, MTK_DP_AUX_P0_3628) &
AUX_RX_PHY_STATE_AUX_TX_P0_MASK;
if (phy_status != AUX_RX_PHY_STATE_AUX_TX_P0_RX_IDLE) {
@@ -2071,7 +2070,7 @@ static ssize_t mtk_dp_aux_transfer(struct drm_dp_aux *mtk_aux,
ret = mtk_dp_aux_do_transfer(mtk_dp, is_read, request,
msg->address + accessed_bytes,
msg->buffer + accessed_bytes,
- to_access);
+ to_access, &msg->reply);
if (ret) {
drm_info(mtk_dp->drm_dev,
@@ -2081,7 +2080,6 @@ static ssize_t mtk_dp_aux_transfer(struct drm_dp_aux *mtk_aux,
accessed_bytes += to_access;
} while (accessed_bytes < msg->size);
- msg->reply = DP_AUX_NATIVE_REPLY_ACK | DP_AUX_I2C_REPLY_ACK;
return msg->size;
err:
msg->reply = DP_AUX_NATIVE_REPLY_NACK | DP_AUX_I2C_REPLY_NACK;
--
2.39.2
