From: Zeyu Fan <Zeyu.Fan@amd.com>
Date: Wed, 19 Jul 2017 16:46:42 -0400
Subject: drm/amd/display: Set i2c speed to 100khz for DCE11.2 and later.
Git-commit: 3d696cbfd48f20d482f2aab2c65ce3a540debd89
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Signed-off-by: Zeyu Fan <Zeyu.Fan@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/dc/i2caux/i2caux.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/display/dc/i2caux/i2caux.c
+++ b/drivers/gpu/drm/amd/display/dc/i2caux/i2caux.c
@@ -337,6 +337,9 @@ enum {
 	DEFAULT_I2C_SW_SPEED = 50,
 	DEFAULT_I2C_HW_SPEED = 50,
 
+	DEFAULT_I2C_SW_SPEED_100KHZ = 100,
+	DEFAULT_I2C_HW_SPEED_100KHZ = 100,
+
 	/* This is the timeout as defined in DP 1.2a,
 	 * 2.3.4 "Detailed uPacket TX AUX CH State Description". */
 	AUX_TIMEOUT_PERIOD = 400,
@@ -436,8 +439,13 @@ bool dal_i2caux_construct(
 	i2caux->aux_timeout_period =
 		SW_AUX_TIMEOUT_PERIOD_MULTIPLIER * AUX_TIMEOUT_PERIOD;
 
-	i2caux->default_i2c_sw_speed = DEFAULT_I2C_SW_SPEED;
-	i2caux->default_i2c_hw_speed = DEFAULT_I2C_HW_SPEED;
+	if (ctx->dce_version >= DCE_VERSION_11_2) {
+		i2caux->default_i2c_hw_speed = DEFAULT_I2C_HW_SPEED_100KHZ;
+		i2caux->default_i2c_sw_speed = DEFAULT_I2C_SW_SPEED_100KHZ;
+	} else {
+		i2caux->default_i2c_hw_speed = DEFAULT_I2C_HW_SPEED;
+		i2caux->default_i2c_sw_speed = DEFAULT_I2C_SW_SPEED;
+	}
 
 	return true;
 }