Commit ebbd857e authored Dec 26, 2011 by Keith Packard Committed by Linus Torvalds Dec 26, 2011

drm/i915: Disable semaphores by default on SNB



Semaphores still cause problems on some machines:

> From Udo Steinberg:
>
> With Linux-3.2-rc6 I'm frequently seeing GPU hangs when large amounts of
> text scroll in an xterm, such as when extracting a tar archive. Such as this
> one (note the timestamps):
>
>  I can reproduce it fairly easily with something
>  as simple as:
>
>	  while true; do dmesg; done

This patch turns them off on SNB while leaving them on for IVB.

Reported-by: Udo Steinberg <udo@hypervisor.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Eugeni Dodonov <eugeni@dodonov.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7f54492f

drivers/gpu/drm/i915/i915_gem_execbuffer.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -756,9 +756,9 @@ intel_enable_semaphores(struct drm_device *dev)
		if (i915_semaphores >= 0)
		return i915_semaphores;

		/* Enable semaphores on SNB when IO remapping is off */
		/* Disable semaphores on SNB */
		if (INTEL_INFO(dev)->gen == 6)
		return !intel_iommu_enabled;
		return 0;

		return 1;
		}