From: Xinlei Lee xinlei.lee@mediatek.com
[ 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@mediatek.com Link: https://patchwork.kernel.org/project/linux-mediatek/patch/1680072203-10394-1... Signed-off-by: Chun-Kuang Hu chunkuang.hu@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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;