Attachment 113131 Details for Bug 88910 – drm/i915: Take runtime pm reference on hangcheck_info

[patch] drm/i915: Take runtime pm reference on hangcheck_info

0001-drm-i915-Take-runtime-pm-reference-on-hangcheck_info.patch (text/plain), 3.01 KB, created by Mika Kuoppala on 2015-02-03 18:20:01 UTC

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Creator: Mika Kuoppala

Created: 2015-02-03 18:20:01 UTC

Size: 3.01 KB

patch

obsolete

>From 0cbc0db0e42fc1859a53b50d053825c1f42b201e Mon Sep 17 00:00:00 2001
>From: Mika Kuoppala <mika.kuoppala@intel.com>
>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 <mika.kuoppala@intel.com>
>---
> 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
>

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Attachments on bug 88910: 113033 | 113131

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