From d30df55b3ec069283408b6d3b013bcba52dd03dc Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 14 Jan 2014 10:45:51 -0500
Subject: [PATCH] drm/radeon/dp: sleep after powering up the display
According to the DP 1.1 spec, the sink must power
up within 1ms. Noticed while reviewing Thierry's
drm/dp patches.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/radeon/atombios_dp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c
index 403ca00b8a55..4ad7643fce5f 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -673,9 +673,11 @@ static int radeon_dp_link_train_init(struct radeon_dp_link_train_info *dp_info)
u8 tmp;
/* power up the sink */
- if (dp_info->dpcd[0] >= 0x11)
+ if (dp_info->dpcd[0] >= 0x11) {
radeon_write_dpcd_reg(dp_info->radeon_connector,
DP_SET_POWER, DP_SET_POWER_D0);
+ usleep_range(1000, 2000);
+ }
/* possibly enable downspread on the sink */
if (dp_info->dpcd[3] & 0x1)
--
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