Searched hist:"36703 e79a982c8ce5a8e43833291f2719e92d0d1" (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/drivers/gpu/drm/i915/ |
| H A D | i915_irq.c | diff 36703e79a982c8ce5a8e43833291f2719e92d0d1 Thu Jun 22 05:56:25 CDT 2017 Chris Wilson <chris@chris-wilson.co.uk> drm/i915: Break modeset deadlocks on reset
Trying to do a modeset from within a reset is fraught with danger. We
can fall into a cyclic deadlock where the modeset is waiting on a
previous modeset that is waiting on a request, and since the GPU hung
that request completion is waiting on the reset. As modesetting doesn't
allow its locks to be broken and restarted, or for its *own* reset
mechanism to take over the display, we have to do something very
evil instead. If we detect that we are stuck waiting to prepare the
display reset (by using a very simple timeout), resort to cancelling all
in-flight requests and throwing the user data into /dev/null, which is
marginally better than the driver locking up and keeping that data to
itself.
This is not a fix; this is just a workaround that unbreaks machines
until we can resolve the deadlock in a way that doesn't lose data!
v2: Move the retirement from set-wegded to the i915_reset() error path,
after which we no longer any delayed worker cleanup for
i915_handle_error()
v3: C abuse for syntactic sugar
v4: Cover all waits with the timeout to catch more driver breakage
References: https://bugs.freedesktop.org/show_bug.cgi?id=99093
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170622105625.16952-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
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| H A D | i915_gem.c | diff 36703e79a982c8ce5a8e43833291f2719e92d0d1 Thu Jun 22 05:56:25 CDT 2017 Chris Wilson <chris@chris-wilson.co.uk> drm/i915: Break modeset deadlocks on reset
Trying to do a modeset from within a reset is fraught with danger. We
can fall into a cyclic deadlock where the modeset is waiting on a
previous modeset that is waiting on a request, and since the GPU hung
that request completion is waiting on the reset. As modesetting doesn't
allow its locks to be broken and restarted, or for its *own* reset
mechanism to take over the display, we have to do something very
evil instead. If we detect that we are stuck waiting to prepare the
display reset (by using a very simple timeout), resort to cancelling all
in-flight requests and throwing the user data into /dev/null, which is
marginally better than the driver locking up and keeping that data to
itself.
This is not a fix; this is just a workaround that unbreaks machines
until we can resolve the deadlock in a way that doesn't lose data!
v2: Move the retirement from set-wegded to the i915_reset() error path,
after which we no longer any delayed worker cleanup for
i915_handle_error()
v3: C abuse for syntactic sugar
v4: Cover all waits with the timeout to catch more driver breakage
References: https://bugs.freedesktop.org/show_bug.cgi?id=99093
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170622105625.16952-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
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