Intel modesetting and tearing

[Greg V]

On Thu, Jan 10, 2019 at 9:22 PM, Johannes Lundberg <johalun0 at gmail.com> 
wrote:
> On Thu, Jan 10, 2019 at 16:03 Christian Weisgerber 
> <naddy at mips.inka.de <mailto:naddy at mips.inka.de>>
> wrote:
> 
>>  I recently switched from an obsolescent Radeon card to the built-in
>>  Intel HD Graphics P4600 with i915kms.ko and the modesetting driver.
>>  That works fine, but there is very noticeable tearing whenever
>>  something moves on-screen.  If you google for it, you'll find plenty
>>  of complaints on Linux, so this is not a FreeBSD issue.
>> 
>>  For MPlayer, replacing the default Xvideo with GL video output (-vo 
>> gl)
>>  eliminates tearing.
>> 
>>  And as I found out just today and quite by accident, in Firefox
>>  toggling layers.acceleration.force-enabled to true will also 
>> eliminate
>>  all tearing, whether from soft-scrolling or when playing YouTube
>>  videos.  Hallelujah!
> 
> 
> Woot?! You mean I can use modesetting AND have tearfree Firefox? 
> Thanks for
> the tip!! I will use this until I switch i3 -> Sway.

When I still used X on my Intel laptop (of course with the modesetting 
DDX), I don't think GL acceleration of Firefox helped with tearing. (I 
always used GL accelerated Firefox anyway.)

The solution was fiddling with compton flags, IIRC '--backend glx 
--vsync opengl-swc' was enough for the Intel GPU