[PATCH 01/35] drm/amd/display: Use udelay when waiting between aux retries

[Wentland, Harry]

On 2019-02-01 3:47 p.m., sylvain.bertrand at gmail.com wrote:
> On Fri, Feb 01, 2019 at 08:08:30PM +0000, sylvain.bertrand at gmail.com wrote:
>> Do you mean non-DC displayport related code is already using udelay instead
>> of msleep on linux?
> 
> I grep-ed amdgpu displayport atombios code, got udelay(400) only.
> Did the same on drm *_dp_* files, got similar udelays with only a very slow
> msleep (which seems justified there).
> 
> But I did not get any udelays with the range of 1ms for "retries". Maybe it
> would be a good idea to a similar delay on non-DC displayport code? That would
> give more time to "slow" displayort monitors to timeout on their side.
> 

DRM's AUX code uses usleep_range in drm_dp_dpcd_access.

Harry