Re: Machine crashes right *after* ~successful resume

[Yinghai Lu]

On Tue, Oct 21, 2014 at 2:40 PM, Wilmer van der Gaast <wilmer@xxxxxxxxx> wrote:
> Hello,
>
> Sorry for the delay, finally poked at this again. It looks like the
> no_console_suspend flag was causing troubles, which I didn't really need
> anyway with logging going to my serial port.
>
> This is what I get now on the failing resume:
>
> [  112.879390] PM: resume of devices complete after 2239.905 msecs
> [  112.880068] r8169 0000:07:00.0 eth0: link up
> [  112.880078] Switched to clocksource hpet
> [  116.069248] PM: Finishing wakeup.
> [  116.072574] Restarting tasks ... done.
> [  116.076664] PM: calling nb rcu_pm_notify+0x0/0x60
> [  116.081439] PM: ... nb rcu_pm_notify+0x0/0x60 done
> [  116.086267] PM: calling nb cpu_hotplug_pm_callback+0x0/0x50
> [  116.088526] systemd[1]: Got notification message for unit
> systemd-journald.service
> [  116.099442] PM: ... nb cpu_hotplug_pm_callback+0x0/0x50 done
> [  116.105099] PM: calling nb fw_pm_notify+0x0/0x150
> [  116.109812] PM: ... nb fw_pm_notify+0x0/0x150 done
> [  116.114623] PM: calling nb bsp_pm_callback+0x0/0x50
> [  116.119504] PM: ... nb bsp_pm_callback+0x0/0x50 done
>
> And then nothing, and it's hung. Looks the same to me (apart from the tsc
> issues + hpet switch) as a successful resume:

then it stuck in pm_restore_console()?

Please check attached debut patch.

Thanks

Yinghai
---
 kernel/power/console.c |    9 +++++++++
 1 file changed, 9 insertions(+)

Index: linux-2.6/kernel/power/console.c
===================================================================
--- linux-2.6.orig/kernel/power/console.c
+++ linux-2.6/kernel/power/console.c
@@ -51,6 +51,7 @@ void pm_vt_switch_required(struct device
 		if (tmp->dev == dev) {
 			/* already registered, update requirement */
 			tmp->required = required;
+			dev_info(dev, "pm_vt_switch_required() update %d\n", required);
 			goto out;
 		}
 	}
@@ -61,6 +62,7 @@ void pm_vt_switch_required(struct device
 
 	entry->required = required;
 	entry->dev = dev;
+	dev_info(dev, "pm_vt_switch_required() added %d\n", required);
 
 	list_add(&entry->head, &pm_vt_switch_list);
 out:
@@ -81,6 +83,7 @@ void pm_vt_switch_unregister(struct devi
 	mutex_lock(&vt_switch_mutex);
 	list_for_each_entry(tmp, &pm_vt_switch_list, head) {
 		if (tmp->dev == dev) {
+			dev_info(dev, "pm_vt_switch_required() removed %d\n", tmp->required);
 			list_del(&tmp->head);
 			kfree(tmp);
 			break;
@@ -131,11 +134,14 @@ int pm_prepare_console(void)
 	if (!pm_vt_switch())
 		return 0;
 
+	pr_info("pm_prepare_console() before move\n");
 	orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1);
 	if (orig_fgconsole < 0)
 		return 1;
 
+	pr_info("pm_prepare_console() before redirect\n");
 	orig_kmsg = vt_kmsg_redirect(SUSPEND_CONSOLE);
+	pr_info("pm_prepare_console() done\n");
 	return 0;
 }
 
@@ -145,7 +151,10 @@ void pm_restore_console(void)
 		return;
 
 	if (orig_fgconsole >= 0) {
+		pr_info("pm_restore_console() before move\n");
 		vt_move_to_console(orig_fgconsole, 0);
+		pr_info("pm_restore_console() before redirect\n");
 		vt_kmsg_redirect(orig_kmsg);
+		pr_info("pm_restore_console() done\n");
 	}
 }