Re: Only fallback mode with kernel 3.16

[jan jgc homeip net]

On 2014-09-13 21:31, Jan Niggemann wrote:
> Hi list,
>
> I'm currently looking into a weird behavior with GNOME 3 starting in
> fallback mode every now and then.
> I only experience this issue with the latest 3.16 kernel, I suspect
> an issue with my graphics driver.
> There are no issues using 3.14.18 instead, perhaps there's less video
> RAM available when running kernel 3.16...
>
> To debug, I need to know when, why GNOME starts in fallback mode
> (using llvmpipe).
>
> Debian stable, 32bit, Lenovo T400
> GNOME Shell 3.4.2

You might find your answer in dmesg. On Archlinux we have several open 
bugreports about intel drivers not working with 3.16.x. Fixes for most 
issues are available, but still not merged in 3.16 stable branch.

Also keep in mind that xf86-video-intel, kernel (DRI subsystem) and 
mesa are under constant development. It's possible that a change in the 
kernel breaks something in older versions of mesa or xf86-video-intel.