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)) { + 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
