Etnaviv crashes on glmark2

[Lucas Stach]

Am Dienstag, den 22.08.2017, 12:59 -0300 schrieb Fabio Estevam:
> On Tue, Aug 22, 2017 at 9:47 AM, Fabio Estevam <festevam at gmail.com> wrote:
> > Hi,
> >
> > I am running kernel 4.12.8 and mesa 17.1.6 on a imx6q, but glmark2
> > never runs successfully until the end. It always crashes like this:
> >
> > ** Failed to set swap interval. Results may be bounded above by refresh rate.
> > [conditionals] fragment-steps=0:vertex-steps=0: FPS: 63 FrameTime: 15.873 ms
> > [  288.732107] Unable to handle kernel paging request at virtual
> > address 00e71a74
> > [  288.739394] pgd = ee52c000
> > [  288.742115] [00e71a74] *pgd=00000000
> > [  288.745782] Internal error: Oops: 5 [#1] SMP ARM
> > [  288.750409] Modules linked in:
> > [  288.753481] CPU: 0 PID: 221 Comm: glmark2-es2-drm Not tainted 4.12.8 #1
> > [  288.760101] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
> > [  288.766635] task: ee420c40 task.stack: ee4f0000
> > [  288.771181] PC is at page_mapping+0xc/0xa4
> > [  288.775291] LR is at set_page_dirty+0x14/0xc8
> 
> If I use the generic drm_gem_cma_free_object() function instead the
> error does not happen anymore:
> https://pastebin.com/edx37jNG
> 
> Not sure if this is a valid fix though. Any comments?

Etnaviv isn't CMA based, so this is certainly not a valid fix. It
probably doesn't crash anymore, as it isn't properly freeing the pages
backing the GEM object.

I've seen this crash in the early days of etnaviv a few times, but it
hasn't happened to me in a long time.

Regards,
Lucas