commit 34dcf173c5f6256210741c0c83bbebf4e017d5ad
author Benoit Goby <benoit@android.com> Fri Jan 21 15:53:44 2011 -0800
committer Colin Cross <ccross@android.com> Tue Jun 14 09:09:50 2011 -0700
tree 12a8ea05b17a897c5013a36b1e30de98a366f610
parent 0ee5695f24a1629c4147ed44650fe8847891efde

PM: Dump suspend thread stack on dpm suspend timeout

When a driver takes more than 3 seconds to suspend, dump the suspend
thread stack since BUG() might only dump the idle thread stack.

Change-Id: If854db355fdcf3b773ea20b1b5e031def6d4b114
Signed-off-by: Benoit Goby <benoit@android.com>

drivers/base/power/main.c

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index abd3e56..3e4d364 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -52,6 +52,10 @@
 
 static void dpm_drv_timeout(unsigned long data);
 static DEFINE_TIMER(dpm_drv_wd, dpm_drv_timeout, 0, 0);
+static struct {
+	struct device *dev;
+	struct task_struct *tsk;
+} dpm_drv_wd_data;
 
 static int async_error;
 
@@ -588,10 +592,15 @@
  */
 static void dpm_drv_timeout(unsigned long data)
 {
-	struct device *dev = (struct device *) data;
+	struct device *dev = dpm_drv_wd_data.dev;
+	struct task_struct *tsk = dpm_drv_wd_data.tsk;
 
 	printk(KERN_EMERG "**** DPM device timeout: %s (%s)\n", dev_name(dev),
 	       (dev->driver ? dev->driver->name : "no driver"));
+
+	printk(KERN_EMERG "dpm suspend stack:\n");
+	show_stack(tsk, NULL);
+
 	BUG();
 }
 
@@ -602,7 +611,9 @@
  */
 static void dpm_drv_wdset(struct device *dev)
 {
-	dpm_drv_wd.data = (unsigned long) dev;
+	dpm_drv_wd_data.dev = dev;
+	dpm_drv_wd_data.tsk = get_current();
+	dpm_drv_wd.data = (unsigned long) &dpm_drv_wd_data;
 	mod_timer(&dpm_drv_wd, jiffies + (HZ * 3));
 }