[Intel-gfx] [PATCH 0/1] drm/i915: Fix races on fbdev [RESEND FOR CI]

[Lukas Wunner]

Originally submitted inline with <20160205145831.GA14084 at wunner.de>,
hereby resubmitted standalone for CI as requested by Daniel with
<20160215163251.GR11240 at phenom.ffwll.local>.

Above-mentioned message contained the following important note:

> However AFAICT a corner case remains where we're still vulnerable to races:
> async_schedule() runs synchronously "if we're out of memory or if there's
> too much work pending already" (see __async_schedule() in kernel/async.c).
> In this case no entry is added to the pending list and
> async_synchronize_full() might theoretically return before the synchronously
> executed function has finished.
>
> The existing call to async_synchronize_full() in intel_fbdev_fini()
> seems to be susceptible to the same race condition, but it's probably
> very hard to trigger it. (Unload the module before the fbdev is fully
> initialized.)
>
> To make it bullet proof we could declare a completion in intel_fbdev.c
> and wait for that instead. Opinions?


Lukas Wunner (1):
  drm/i915: Fix races on fbdev

 drivers/gpu/drm/i915/i915_dma.c    | 8 +++-----
 drivers/gpu/drm/i915/intel_fbdev.c | 4 ++++
 2 files changed, 7 insertions(+), 5 deletions(-)

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1.8.5.2 (Apple Git-48)