On 28-03-2022 15:52, Anshuman Gupta wrote:
i915 doesn't use pm_suspend_ignore_children() which warrants that
any runtime active child of i915 will block the runtime suspend
of i915.
i915_runtime_pm_status only exposes i915 runtime pm usage_count,
which is not sufficient to debug in the scenarios when i915 has
zero usage_count but there are runtime active children.
Dump i915 child's runtime pm status to debug such
i915 runtime suspend issues.
Cc: Chris Wilson <chris.p.wilson@xxxxxxxxx>
Signed-off-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_debugfs.c | 38 +++++++++++++++++++++++++++++
1 file changed, 38 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 445b4da23950..ea1730419f8d 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -483,6 +483,40 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
return 0;
}
+#ifdef CONFIG_PM
+static int i915_runtime_dump_child_status(struct device *dev, void *data)
+{
+ struct seq_file *m = data;
+ const char *rpm_status;
+
+ /* Early return if runtime_pm is disabled */
+ if (dev->power.disable_depth)
+ return 0;
+
+ switch (dev->power.runtime_status) {
+ case RPM_SUSPENDED:
+ rpm_status = "suspended";
+ break;
+ case RPM_SUSPENDING:
+ rpm_status = "suspending";
+ break;
+ case RPM_RESUMING:
+ rpm_status = "resuming";
+ break;
+ case RPM_ACTIVE:
+ rpm_status = "active";
+ break;
+ default:
+ rpm_status = "unknown";
+ }
+
+ seq_printf(m, "\t%s %s: Runtime status: %s\n", dev_driver_string(dev),
+ dev_name(dev), rpm_status);
+
+ return 0;
+}
+#endif
+
static int i915_runtime_pm_status(struct seq_file *m, void *unused)
{
struct drm_i915_private *dev_priv = node_to_i915(m->private);
@@ -500,6 +534,10 @@ static int i915_runtime_pm_status(struct seq_file *m, void *unused)
#ifdef CONFIG_PM
seq_printf(m, "Usage count: %d\n",
atomic_read(&dev_priv->drm.dev->power.usage_count));
+ seq_printf(m, "Runtime active children: %d\n",
+ atomic_read(&dev_priv->drm.dev->power.child_count));
+ device_for_each_child(&pdev->dev, m, i915_runtime_dump_child_status);
+
These changes looks fine to me.
Reviewed-by: Badal Nilawar <badal.nilawar@xxxxxxxxx>
#else
seq_printf(m, "Device Power Management (CONFIG_PM) disabled\n");
#endif
