[PATCH AUTOSEL 4.19 20/81] drm/amd/display: extending AUX SW Timeout

Sasha Levin
2019-05-07T05:36:40Z

From: Martin Leung <martin.leung@amd.com>

[ Upstream commit f4bbebf8e7eb4d294b040ab2d2ba71e70e69b930 ]

[Why]
AUX takes longer to reply when using active DP-DVI dongle on some asics
resulting in up to 2000+ us edid read (timeout).

[How]
1. Adjust AUX poll to match spec
2. Extend the SW timeout. This does not affect normal
operation since we exit the loop as soon as AUX acks.

Signed-off-by: Martin Leung <martin.leung@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Joshua Aberback <Joshua.Aberback@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/display/dc/dce/dce_aux.c | 9 ++++++---
drivers/gpu/drm/amd/display/dc/dce/dce_aux.h | 6 +++---
2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
index 3f5b2e6f7553..df936edac5c7 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
@@ -189,6 +189,12 @@ static void submit_channel_request(
1,
0);
}
+
+ REG_UPDATE(AUX_INTERRUPT_CONTROL, AUX_SW_DONE_ACK, 1);
+
+ REG_WAIT(AUX_SW_STATUS, AUX_SW_DONE, 0,
+ 10, aux110->timeout_period/10);
+
/* set the delay and the number of bytes to write */

/* The length include
@@ -241,9 +247,6 @@ static void submit_channel_request(
}
}

- REG_UPDATE(AUX_INTERRUPT_CONTROL, AUX_SW_DONE_ACK, 1);
- REG_WAIT(AUX_SW_STATUS, AUX_SW_DONE, 0,
- 10, aux110->timeout_period/10);
REG_UPDATE(AUX_SW_CONTROL, AUX_SW_GO, 1);
}

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.h b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.h
index f7caab85dc80..2c6f50b4245a 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.h
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.h
@@ -69,11 +69,11 @@ enum { /* This is the timeout as defined in DP 1.2a,
* at most within ~240usec. That means,
* increasing this timeout will not affect normal operation,
* and we'll timeout after
- * SW_AUX_TIMEOUT_PERIOD_MULTIPLIER * AUX_TIMEOUT_PERIOD = 1600usec.
+ * SW_AUX_TIMEOUT_PERIOD_MULTIPLIER * AUX_TIMEOUT_PERIOD = 2400usec.
* This timeout is especially important for
- * resume from S3 and CTS.
+ * converters, resume from S3, and CTS.
*/
- SW_AUX_TIMEOUT_PERIOD_MULTIPLIER = 4
+ SW_AUX_TIMEOUT_PERIOD_MULTIPLIER = 6
};
struct aux_engine_dce110 {
struct aux_engine base;
--
2.20.1