From 0cbc0db0e42fc1859a53b50d053825c1f42b201e Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Tue, 3 Feb 2015 18:04:39 +0200 Subject: [PATCH] drm/i915: Take runtime pm reference on hangcheck_info 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 Signed-off-by: Mika Kuoppala --- 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 211d494..04ae72b 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