On Thu, Feb 05, 2015 at 12:16:32PM +0200, Mika Kuoppala wrote: > We read the coherent current seqno and actual head from ring. > For hardware access we need to take runtime_pm reference, which brings in > locking. As this debugfs entry is for debugging hangcheck behaviour, > including locking problems, we need to be flexible on taking them. > > Try to see if we get a lock and if so, get seqno and actual head > from hardware. If we don't have exclusive access, get lazy coherent > seqno and print token acthd for which the user can see that the > seqno is of different nature. > > Testcase: igt/pm_rpm/debugfs-read > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88910 > Tested-by: Ding Heng <hengx.ding@xxxxxxxxx> > Signed-off-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_debugfs.c | 26 +++++++++++++++++++++++--- > 1 file changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > index 9af17fb..5a6b0e2 100644 > --- a/drivers/gpu/drm/i915/i915_debugfs.c > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > @@ -1223,8 +1223,11 @@ out: > static int i915_hangcheck_info(struct seq_file *m, void *unused) > { > struct drm_info_node *node = m->private; > - struct drm_i915_private *dev_priv = to_i915(node->minor->dev); > + struct drm_device *dev = node->minor->dev; > + struct drm_i915_private *dev_priv = dev->dev_private; > struct intel_engine_cs *ring; > + u64 acthd[I915_NUM_RINGS]; > + u32 seqno[I915_NUM_RINGS]; > int i; > > if (!i915.enable_hangcheck) { > @@ -1232,6 +1235,23 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused) > return 0; > } > > + if (mutex_trylock(&dev->struct_mutex)) { Why do we need dev->struct_mutex here? -Daniel > + intel_runtime_pm_get(dev_priv); > + > + for_each_ring(ring, dev_priv, i) { > + seqno[i] = ring->get_seqno(ring, false); > + acthd[i] = intel_ring_get_active_head(ring); > + } > + > + intel_runtime_pm_put(dev_priv); > + mutex_unlock(&dev->struct_mutex); > + } else { > + for_each_ring(ring, dev_priv, i) { > + seqno[i] = ring->get_seqno(ring, true); > + acthd[i] = -1; > + } > + } > + > if (delayed_work_pending(&dev_priv->gpu_error.hangcheck_work)) { > seq_printf(m, "Hangcheck active, fires in %dms\n", > jiffies_to_msecs(dev_priv->gpu_error.hangcheck_work.timer.expires - > @@ -1242,12 +1262,12 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused) > for_each_ring(ring, dev_priv, i) { > seq_printf(m, "%s:\n", ring->name); > seq_printf(m, "\tseqno = %x [current %x]\n", > - ring->hangcheck.seqno, ring->get_seqno(ring, false)); > + ring->hangcheck.seqno, seqno[i]); > seq_printf(m, "\taction = %d\n", ring->hangcheck.action); > seq_printf(m, "\tscore = %d\n", ring->hangcheck.score); > seq_printf(m, "\tACTHD = 0x%08llx [current 0x%08llx]\n", > (long long)ring->hangcheck.acthd, > - (long long)intel_ring_get_active_head(ring)); > + (long long)acthd[i]); > seq_printf(m, "\tmax ACTHD = 0x%08llx\n", > (long long)ring->hangcheck.max_acthd); > } > -- > 1.9.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
