[PATCH] pm: print name of failed suspend function

Print more diagnostic info to help identify the source of power management
suspend failures.

Example:

usb_hcd_pci_suspend(): pci_set_power_state+0x0/0x1af() returns -22
pci_device_suspend(): usb_hcd_pci_suspend+0x0/0x11b() returns -22
suspend_device(): pci_device_suspend+0x0/0x34() returns -22

Work-in-progress.  It needs lots more suspend_report_result() calls sprinkled
everywhere.

Cc: Patrick Mochel <mochel@digitalimplant.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@suspend2.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

5 files changed, 31 insertions, 8 deletions

diff --git a/drivers/base/power/suspend.c b/drivers/base/power/suspend.c
index bdb60663f2ef..662209d3f42d 100644
--- a/drivers/base/power/suspend.c
+++ b/drivers/base/power/suspend.c
@@ -10,6 +10,8 @@
 
 #include <linux/vt_kern.h>
 #include <linux/device.h>
+#include <linux/kallsyms.h>
+#include <linux/pm.h>
 #include "../base.h"
 #include "power.h"
 
@@ -58,6 +60,7 @@ int suspend_device(struct device * dev, pm_message_t state)
         if (dev->bus && dev->bus->suspend && !dev->power.power_state.event) {
                 dev_dbg(dev, "suspending\n");
                 error = dev->bus->suspend(dev, state);
+                suspend_report_result(dev->bus->suspend, error);
         }
         up(&dev->sem);
         return error;
@@ -169,3 +172,12 @@ int device_power_down(pm_message_t state)
 
 EXPORT_SYMBOL_GPL(device_power_down);
 
+void __suspend_report_result(const char *function, void *fn, int ret)
+{
+        if (ret) {
+                printk(KERN_ERR "%s(): ", function);
+                print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn);
+                printk("%d\n", ret);
+        }
+}
+EXPORT_SYMBOL_GPL(__suspend_report_result);
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index f22f69ac6445..1456759936c5 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -271,10 +271,12 @@ static int pci_device_suspend(struct device * dev, pm_message_t state)
         struct pci_driver * drv = pci_dev->driver;
         int i = 0;
 
-        if (drv && drv->suspend)
+        if (drv && drv->suspend) {
                 i = drv->suspend(pci_dev, state);
-        else
+                suspend_report_result(drv->suspend, i);
+        } else {
                 pci_save_state(pci_dev);
+        }
         return i;
 }
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index bea1ad1ad5ba..042fa5265cf6 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -307,9 +307,11 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)
          * Can enter D0 from any state, but if we can only go deeper 
          * to sleep if we're already in a low power state
          */
-        if (state != PCI_D0 && dev->current_state > state)
+        if (state != PCI_D0 && dev->current_state > state) {
+                printk(KERN_ERR "%s(): %s: state=%d, current state=%d\n",
+                        __FUNCTION__, pci_name(dev), state, dev->current_state);
                 return -EINVAL;
-        else if (dev->current_state == state) 
+        } else if (dev->current_state == state)
                 return 0;        /* we're already there */
 
         /* find PCI PM capability in list */
diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index 0d2193b69235..66b78404ab34 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -213,11 +213,9 @@ int usb_hcd_pci_suspend (struct pci_dev *dev, pm_message_t message)
 
         if (hcd->driver->suspend) {
                 retval = hcd->driver->suspend(hcd, message);
-                if (retval) {
-                        dev_dbg (&dev->dev, "PCI pre-suspend fail, %d\n",
-                                retval);
+                suspend_report_result(hcd->driver->suspend, retval);
+                if (retval)
                         goto done;
-                }
         }
         synchronize_irq(dev->irq);
 
@@ -263,6 +261,7 @@ int usb_hcd_pci_suspend (struct pci_dev *dev, pm_message_t message)
                  * some device state (e.g. as part of clock reinit).
                  */
                 retval = pci_set_power_state (dev, PCI_D3hot);
+                suspend_report_result(pci_set_power_state, retval);
                 if (retval == 0) {
                         int wake = device_can_wakeup(&hcd->self.root_hub->dev);
 
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 6df2585c0169..66be58902b17 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -199,6 +199,12 @@ extern int device_suspend(pm_message_t state);
 
 extern int dpm_runtime_suspend(struct device *, pm_message_t);
 extern void dpm_runtime_resume(struct device *);
+extern void __suspend_report_result(const char *function, void *fn, int ret);
+
+#define suspend_report_result(fn, ret)                                  \
+        do {                                                            \
+                __suspend_report_result(__FUNCTION__, fn, ret);         \
+        } while (0)
 
 #else /* !CONFIG_PM */
 
@@ -219,6 +225,8 @@ static inline void dpm_runtime_resume(struct device * dev)
 {
 }
 
+#define suspend_report_result(fn, ret) do { } while (0)
+
 #endif
 
 /* changes to device_may_wakeup take effect on the next pm state change.