From d30df55b3ec069283408b6d3b013bcba52dd03dc Mon Sep 17 00:00:00 2001 From: Alex Deucher 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 --- 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) -- 2.20.1