On Wed, Jul 19, 2017 at 4:05 PM, Daniel Vetter daniel.vetter@ffwll.ch wrote:
On Wed, Jul 19, 2017 at 3:42 PM, Chris Wilson chris@chris-wilson.co.uk wrote:
Quoting Daniel Vetter (2017-07-19 13:54:58)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 5aa7ca1ab592..4762f158032d 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3471,10 +3471,9 @@ 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);
/* We have a modeset vs reset deadlock, defensively unbreak it. */set_bit(I915_RESET_MODESET, &dev_priv->gpu_error.flags);wake_up_all(&dev_priv->gpu_error.wait_queue);How are we breaking the
modeset_lock -> struct_mutex -> wait_on_reset ?We wait the modeset_lock next which stops the reset from proceeding, and so the deadlock persists until the wedge-me timeout?
Hm indeed, I didn't check my logs carefully enough and there's still "i915_reset_device timed out" in it. But I also thought the only real wait we have left for the gpu is the one under i915_sw_fence. I think we could simply switch i915_mutex_lock_interruptible calls in atomic modeset over mutex_lock_interruptible? Or is there another can of worms I'm missing?
Obviously, because that's what we're doing already. But I don't have the DRM_ERROR from i915_gem_wait_for_error anywhere in my logs either, so not clear what exactly is going on ... -Daniel