linux-kernel - [PATCH] drm/i915: Disable semaphores by default on SNB

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1324675987-31033-1-git-send-email-keithp@keithp.com>
Date:	Fri, 23 Dec 2011 13:33:07 -0800
From:	Keith Packard <keithp@...thp.com>
To:	intel-gfx@...ts.freedesktop.org
Cc:	linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
	Keith Packard <keithp@...thp.com>,
	Daniel Vetter <daniel@...ll.ch>,
	Eugeni Dodonov <eugeni@...onov.net>
Subject: [PATCH] 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@...ervisor.org>
Cc: Daniel Vetter <daniel@...ll.ch>
Cc: Eugeni Dodonov <eugeni@...onov.net>
Signed-off-by: Keith Packard <keithp@...thp.com>
---
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index c681dc1..0d4d308 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -758,7 +758,7 @@ intel_enable_semaphores(struct drm_device *dev)
 
 	/* Enable semaphores on SNB when IO remapping is off */
 	if (INTEL_INFO(dev)->gen == 6)
-		return !intel_iommu_enabled;
+		return 0;
 
 	return 1;
 }
-- 
1.7.7.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/