From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date: Wed, 27 Sep 2023 19:06:41 +0000 (-0400)
Subject: drm/amd/display: Don't use fsleep for PSR exit waits
X-Git-Tag: v6.5.11~29
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=07256dc046b1be329940f9516c0ae74eec09a9f0;p=thirdparty%2Fkernel%2Fstable.git

drm/amd/display: Don't use fsleep for PSR exit waits

[ Upstream commit 79df45dc4bfb13d9bd3a75338b9d9dab948be3d6 ]

[Why]
These functions can be called from high IRQ levels and the OS will hang
if it tries to use a usleep_highres or a msleep.

[How]
Replace the fsleep with a udelay.

Reviewed-by: Aric Cyr <aric.cyr@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
index 63009db8b5a72..d156eeef466f9 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c
@@ -586,7 +586,8 @@ static void dcn10_dmcu_set_psr_enable(struct dmcu *dmcu, bool enable, bool wait)
 				if (state == PSR_STATE0)
 					break;
 			}
-			fsleep(500);
+			/* must *not* be fsleep - this can be called from high irq levels */
+			udelay(500);
 		}
 
 		/* assert if max retry hit */
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
index 0f24b6fbd2201..4704c9c85ee6f 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
@@ -216,7 +216,8 @@ static void dmub_psr_enable(struct dmub_psr *dmub, bool enable, bool wait, uint8
 					break;
 			}
 
-			fsleep(500);
+			/* must *not* be fsleep - this can be called from high irq levels */
+			udelay(500);
 		}
 
 		/* assert if max retry hit */