linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c, branch v3.2

drm/i915: Disable semaphores by default on SNB

2011-12-27T05:07:26Z

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 Cc: Daniel Vetter Cc: Eugeni Dodonov Signed-off-by: Keith Packard Signed-off-by: Linus Torvalds

drm/i915: enable semaphores on per-device defaults

2011-12-16T16:49:59Z

This adds a default setting for semaphores parameter, and enables semaphores by default on IVB. For now, as semaphores interaction with VTd causes random issues on SNB, we do not enable them by default. But they can still be enabled via the semaphores=1 kernel parameter. v2: enables semaphores on SNB when IO remapping is disabled, with base on Keith Packard patch. CC: Daniel Vetter CC: Ben Widawsky CC: Keith Packard CC: Jesse Barnes CC: Chris Wilson Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=42696 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=40564 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41353 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38862 Reviewed-by: Chris Wilson Reviewed-by: Daniel Vetter Signed-off-by: Eugeni Dodonov Signed-off-by: Keith Packard

drm/i915: Dumb down the semaphore logic

2011-09-21T21:52:41Z

While I think the previous code is correct, it was hard to follow and hard to debug. Since we already have a ring abstraction, might as well use it to handle the semaphore updates and compares. I don't expect this code to make semaphores better or worse, but you never know... v2: Remove magic per Keith's suggestions. Ran Daniel's gem_ring_sync_loop test on this. v3: Ignored one of Keith's suggestions. v4: Removed some bloat per Daniel's recommendation. Cc: Daniel Vetter Cc: Keith Packard Signed-off-by: Ben Widawsky Signed-off-by: Keith Packard

Revert "drm/i915: Kill GTT mappings when moving from GTT domain"

2011-06-21T18:11:02Z

This reverts commit 4a684a4117abd756291969336af454e8a958802f. Userland has always been required to set the object's domain to GTT before using it through a GTT mapping, it's not something that the kernel is supposed to enforce. (The pagefault support is so that we can handle multiple mappings without userland having to pin across them, not so that userland can use GTT after GPU domains without telling the kernel). Fixes 19.2% +/- 0.8% (n=6) performance regression in cairo-gl firefox-talos-gfx on my T420 latop. Signed-off-by: Keith Packard

drm/i915: Disable pagefaults along execbuffer relocation fast path

2011-03-23T09:17:01Z

Along the fast path for relocation handling, we attempt to copy directly from the user data structures whilst holding our mutex. This causes lockdep to warn about circular lock dependencies if we need to pagefault the user pages. [Since when handling a page fault on a mmapped bo, we need to acquire the struct mutex whilst already holding the mm semaphore, it is then verboten to acquire the mm semaphore when already holding the struct mutex. The likelihood of the user passing in the relocations contained in a GTT mmaped bo is low, but conceivable for extreme pathology.] In order to force the mm to return EFAULT rather than handle the pagefault, we therefore need to disable pagefaults across the relocation fast path. Signed-off-by: Chris Wilson Cc: stable@kernel.org Reviewed-by: Daniel Vetter

Merge branch 'drm-intel-fixes' into drm-intel-next

2011-03-07T12:35:15Z

Apply the trivial conflicting regression fixes, but keep GPU semaphores enabled. Conflicts: drivers/gpu/drm/i915/i915_drv.h drivers/gpu/drm/i915/i915_gem_execbuffer.c

drm/i915: Only wait on a pending flip if we intend to write to the buffer

2011-03-07T11:06:02Z

... as if we are only reading from it, we can do that concurrently with the queue flip. Signed-off-by: Chris Wilson

drm/i915: Disable GPU semaphores by default

2011-03-07T11:00:59Z

Andi Kleen narrowed his GPU hangs on his Sugar Bay (SNB desktop) rev 09 down to the use of GPU semaphores, and we already know that they appear broken up to Huron River (mobile) rev 08. (I'm optimistic that disabling GPU semaphores is simply hiding another bug by the latency and side-effects of the additional device interaction it introduces...) However, use of semaphores is a massive performance improvement... Only as long as the system remains stable. Enable at your peril. Reported-by: Andi Kleen Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33921 Signed-off-by: Chris Wilson

drm/i915: Re-enable GPU semaphores for SandyBridge mobile

2011-03-01T19:22:52Z

This seems to be running stably on my test laptop, so hopefully the reported hangs where just symptoms of other bugs. Signed-off-by: Chris Wilson

drm/i915: Allow relocation deltas outside of target bo

2011-03-01T16:01:02Z

Userspace has a legitimate requirement to use a delta that points to outside of the target bo, and so we need to enable this. (As this is an abi break, albeit a relaxation of the current restrictions, mark the change with a new flag.) Signed-off-by: Chris Wilson