[Intel-gfx] [PATCH] drm/i915: Skip fbdev core suspend/resume when fbdev emulation is disabled.

[Bob Paauwe]

On Tue, 28 Jun 2016 16:47:28 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:

> On Tue, Jun 28, 2016 at 08:42:01AM -0700, Bob Paauwe wrote:
> > When fbdev emulation is disabled it is not a good idea to call into
> > the core fb_set_suspend() function as this will cause suspend and
> > resume to fail. Also ifbdev->fb is null so the defeference farther
> > down will oops. Nothing in that path is needed in this case so bail
> > early when ifbdev->fb is null.  
> 
> This function does not exist when fbdev emulation is disabled. I suspect
> you mean something else, so please give the evidence of the problem this
> patch is addressing.
> -Chris
> 

Sorry, I probably should have been more explicit. This happens when you
set "drm_kms_helper.fbdev_emulation=0" on the command line. In that
case the function is called and will crash during a S3 suspend and
probably during hibernation as well. 

You're right, it isn't applicable when the kernel config
CONFIG_DRM_FBDEV_EMULATION is off.

Bob
 
--
Bob Paauwe                  
Bob.J.Paauwe at intel.com
IOTG / PED Software Organization
Intel Corp.  Folsom, CA
(916) 356-6193