From: John Barberiz <John.Barberiz@amd.com>
Date: Wed, 16 Jan 2019 22:21:31 +0000 (-0500)
Subject: drm/amd/display: Use udelay when waiting between aux retries
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=9ca089925f0c318307881eadc0535e7c7a7b5e2d;p=openwrt%2Fstaging%2Fblogic.git

drm/amd/display: Use udelay when waiting between aux retries

[Why]
"IRQ_HPD Pulse Length Test" DP compliance test
fails. Test complains that certain DPCD registers
are not read within 100 ms.

[How]
msleep is inaccurate for small values. Used udelay
instead for accuracy.

Signed-off-by: John Barberiz <John.Barberiz@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

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 adbb22224e1a..4febf4ef7240 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
@@ -516,7 +516,7 @@ bool dce_aux_transfer_with_retries(struct ddc_service *ddc,
 			}
 		}
 
-		msleep(1);
+		udelay(1000);
 	}
 	return false;
 }