From: Benoit Goby <benoit@android.com>
Date: Fri, 21 Jan 2011 23:53:44 +0000 (-0800)
Subject: PM: Dump suspend thread stack on dpm suspend timeout
X-Git-Tag: firefly_0821_release~10785^2~12^2~11
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=10b41e10292b412a3e0cc506cd5344d0898cdab9;p=firefly-linux-kernel-4.4.55.git

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>
---

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 55b9e6bd4f1b..0855a10337ee 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -46,6 +46,10 @@ static DEFINE_MUTEX(dpm_list_mtx);
 
 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;
 
 /*
  * Set once the preparation of devices for a PM transition has started, reset
@@ -446,10 +450,15 @@ static int device_resume(struct device *dev, pm_message_t state)
  */
 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();
 }
 
@@ -460,7 +469,9 @@ static void dpm_drv_timeout(unsigned long data)
  */
 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));
 }