[PATCH 09/16] drm/amd/display: Don't use fsleep for PSR exit waits

[Tom Chung]

From: Nicholas Kazlauskas <nicholas.kazlaus...@amd.com>

[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....@amd.com>
Acked-by: Tom Chung <chiahsuan.ch...@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlaus...@amd.com>
---
 drivers/gpu/drm/amd/display/dc/dce/dce_dmcu.c | 3 ++-
 drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

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 b87bfecb7755..a8e79104b684 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 f27cc8f9d0aa..9d4170a356a2 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dmub_psr.c
@@ -217,7 +217,8 @@ 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 */
-- 
2.25.1