Re: [PATCH] drm/amd/display: replace use of msleep(<20) with usleep_range for better accuracy

[Shuah Khan]

On 3/26/25 01:00, James Flowers wrote:

msleep < 20ms will often sleep for ~20ms (according to 
Documentation/timers/timers-howto.rst).

Can you elaborate and explain why this change is necessary?

Signed-off-by: James Flowers <bold.zone2...@fastmail.com>
---
  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c 
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index 2cd35392e2da..2d225735602b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -682,7 +682,7 @@ static bool execute_synaptics_rc_command(struct drm_dp_aux 
*aux,
                if (rc_cmd == cmd)
                        // active is 0
                        break;
-               msleep(10);
+               usleep_range(10000, 10200);
        }

// read rc result

thanks,
-- Shuah