| Message ID | 20170808080828.23650-1-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index e4af56b5ff27..b2c220ba2575 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3458,6 +3458,13 @@ void intel_prepare_reset(struct drm_i915_private *dev_priv) !gpu_reset_clobbers_display(dev_priv)) return; + /* We have a modeset vs reset deadlock, defensively unbreak it. + * + * FIXME: We can do a _lot_ better, this is just a first iteration. + */ + i915_gem_set_wedged(dev_priv); + DRM_DEBUG_DRIVER("Wedging GPU to avoid deadlocks with pending modeset updates\n"); + /* * Need mode_config.mutex so that we don't * trample ongoing ->detect() and whatnot.
... using the biggest hammer we have. This is essentially a weaponized version of the timeout-based wedging Chris added in commit 36703e79a982c8ce5a8e43833291f2719e92d0d1 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Thu Jun 22 11:56:25 2017 +0100 drm/i915: Break modeset deadlocks on reset Because defense-in-depth is good it's good to still have both. Also note that with the locking change we can now restrict this a lot (old gpus and special testing only), so this doesn't kill the TDR benefits on at least anything remotely modern. And futuremore with a few tricks it should be possible to make a much more educated guess about whether an atomic commit is stuck waiting on the gpu (atomic_t counting the pending i915_sw_fence used by the atomic modeset code should do it), so we can improve this. But for now just start with something that is guaranteed to recover faster, for much better CI througput. This defacto reverts TDR on these platforms, but there's not really a single commit to specify as the sole offender. v2: Add a debug message to explain what's going on. We can't DRM_ERROR because that spams CI. And the timeout based fallback still prints a DRM_ERROR, in case something goes wrong. v3: Fix comment layout (Michel) Fixes: 4680816be336 ("drm/i915: Wait first for submission, before waiting for request completion") Fixes: 221fe7994554 ("drm/i915: Perform a direct reset of the GPU from the waiter") Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v2) Cc: Michel Thierry <michel.thierry@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> (v2) Reviewed-by: Michel Thierry <michel.thierry@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> --- drivers/gpu/drm/i915/intel_display.c | 7 +++++++ 1 file changed, 7 insertions(+)