Commit 9243d70e authored by Xinlei Lee's avatar Xinlei Lee Committed by Chun-Kuang Hu
Browse files

drm/mediatek: dp: Change the aux retries times when receiving AUX_DEFER 



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: f70ac097 ("drm/mediatek: Add MT8195 Embedded DisplayPort driver")
Signed-off-by: default avatarXinlei Lee <xinlei.lee@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/1680072203-10394-1-git-send-email-xinlei.lee@mediatek.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent d6dc3cdc

drivers/gpu/drm/mediatek/mtk_dp.c

+5 −7
Original line number Diff line number Diff line
@@ -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) &

	*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;