From 27ab543d41f1d738542d782a5bd8c35c4fc0cba0 Mon Sep 17 00:00:00 2001
From: Ilya Bakoulin <Ilya.Bakoulin@amd.com>
Date: Thu, 4 Aug 2022 13:44:51 -0400
Subject: drm/amd/display: Change AUX NACK behavior
Git-commit: 95bbbb88ed49f6d4f46c9a23be0ba94db2fa65e9
Patch-mainline: v6.1-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849
[Why]
Retrying on receiving a NACK can result in long overall EDID read times
in some cases.
[How]
Retry only on DEFER and return immediately on NACK.
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: Ilya Bakoulin <Ilya.Bakoulin@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dc/dce/dce_aux.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 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 919c2c2ba84b..32782ef9ef77 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
@@ -814,12 +814,6 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc,
"dce_aux_transfer_with_retries: AUX_RET_SUCCESS: AUX_TRANSACTION_REPLY_I2C_OVER_AUX_DEFER");
retry_on_defer = true;
- fallthrough;
- case AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK:
- if (*payload->reply == AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK)
- DC_TRACE_LEVEL_MESSAGE(DAL_TRACE_LEVEL_INFORMATION,
- LOG_FLAG_I2cAux_DceAux,
- "dce_aux_transfer_with_retries: AUX_RET_SUCCESS: AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK");
if (aux_defer_retries >= AUX_MIN_DEFER_RETRIES
&& defer_time_in_ms >= AUX_MAX_DEFER_TIMEOUT_MS) {
@@ -848,7 +842,11 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc,
}
}
break;
-
+ case AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK:
+ DC_TRACE_LEVEL_MESSAGE(DAL_TRACE_LEVEL_INFORMATION,
+ LOG_FLAG_I2cAux_DceAux,
+ "dce_aux_transfer_with_retries: FAILURE: AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK");
+ goto fail;
case AUX_TRANSACTION_REPLY_I2C_DEFER:
DC_TRACE_LEVEL_MESSAGE(DAL_TRACE_LEVEL_INFORMATION,
LOG_FLAG_I2cAux_DceAux,
--
2.38.1