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.zone2373@xxxxxxxxxxxx>
> ---
>   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