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

Nicholas Kazlauskas · gregkh · commit 80a984854ff0 · 2024-09-08T07:56:38.000+02:00
[ Upstream commit b5236da ] [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 flseep with a udelay for dmub_replay_enable. Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@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/dmub_replay.c b/drivers/gpu/drm/amd/display/dc/dce/dmub_replay.c
@@ -102,7 +102,8 @@ static void dmub_replay_enable(struct dmub_replay *dmub, bool enable, bool wait,
 					break;
 			}
 
-			fsleep(500);
+			/* must *not* be fsleep - this can be called from high irq levels */
+			udelay(500);
 		}
 
 		/* assert if max retry hit */

Original file line number	Diff line number	Diff line change
`@@ -102,7 +102,8 @@ static void dmub_replay_enable(struct dmub_replay *dmub, bool enable, bool wait,`
`102`	`102`	`break;`
`103`	`103`	`}`
`104`	`104`
`105`		`- fsleep(500);`
	`105`	`+ /* must not be fsleep - this can be called from high irq levels */`
	`106`	`+ udelay(500);`
`106`	`107`	`}`
`107`	`108`
`108`	`109`	`/* assert if max retry hit */`