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authorNicholas Kazlauskas <nicholas.kazlauskas@amd.com>2022-09-07 10:11:34 -0400
committerAlex Deucher <alexander.deucher@amd.com>2022-09-27 17:55:44 -0400
commitdd37fba90e72a48998d9f0eb5497088ea2b02ad1 (patch)
tree140d113cca74ec639a45c4f5f5888a4935ad7508 /drivers/gpu
parentb6d1c39bc637fe4879d610e6687b1d4224c4b2fb (diff)
drm/amd/display: Do DIO FIFO enable after DP video stream enable
[Why] Avoids a race condition where DIO FIFO can underflow due to no incoming data available. [How] Shift the FIFO enable below stream enable. Make sure fullness level is written before the DIO reset takes place and that we're not doing it twice. Reviewed-by: Syed Hassan <Syed.Hassan@amd.com> Acked-by: Jasdeep Dhillon <jdhillon@amd.com> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
index 06d8638db696..52b71b2fef67 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c
@@ -56,7 +56,8 @@ static void enc314_enable_fifo(struct stream_encoder *enc)
/* TODO: Confirm if we need to wait for DIG_SYMCLK_FE_ON */
REG_WAIT(DIG_FE_CNTL, DIG_SYMCLK_FE_ON, 1, 10, 5000);
- REG_UPDATE_2(DIG_FIFO_CTRL0, DIG_FIFO_RESET, 1, DIG_FIFO_READ_START_LEVEL, 0x7);
+ REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_READ_START_LEVEL, 0x7);
+ REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_RESET, 1);
REG_WAIT(DIG_FIFO_CTRL0, DIG_FIFO_RESET_DONE, 1, 10, 5000);
REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_RESET, 0);
REG_WAIT(DIG_FIFO_CTRL0, DIG_FIFO_RESET_DONE, 0, 10, 5000);
@@ -316,15 +317,11 @@ static void enc314_stream_encoder_dp_unblank(
/* switch DP encoder to CRTC data, but reset it the fifo first. It may happen
* that it overflows during mode transition, and sometimes doesn't recover.
*/
- REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_READ_START_LEVEL, 0x7);
REG_UPDATE(DP_STEER_FIFO, DP_STEER_FIFO_RESET, 1);
udelay(10);
REG_UPDATE(DP_STEER_FIFO, DP_STEER_FIFO_RESET, 0);
- /* DIG Resync FIFO now needs to be explicitly enabled. */
- enc314_enable_fifo(enc);
-
/* wait 100us for DIG/DP logic to prime
* (i.e. a few video lines)
*/
@@ -340,6 +337,12 @@ static void enc314_stream_encoder_dp_unblank(
REG_UPDATE(DP_VID_STREAM_CNTL, DP_VID_STREAM_ENABLE, true);
+ /*
+ * DIG Resync FIFO now needs to be explicitly enabled.
+ * This should come after DP_VID_STREAM_ENABLE per HW docs.
+ */
+ enc314_enable_fifo(enc);
+
dp_source_sequence_trace(link, DPCD_SOURCE_SEQ_AFTER_ENABLE_DP_VID_STREAM);
}