Subject: Re: [REGRESSION 00/04] Crash during resume of pcie bridge

From: Bert Karwatzki <[email-masked]>
Date: Tue, 07 Oct 2025 08:50:30 +0200

Am Montag, dem 06.10.2025 um 18:22 +0200 schrieb Bert Karwatzki:
> 
> > 
> Even versions that did crash can be stable for 24h of uptime so I think this 
> will take too long.
> I think I've already chased down the crash to this part of rpm_resume()
> (I'm currently doing a testrun with more dev_info()s in this part):
> 
>  skip_parent:
> 
> 	if (!strcmp(dev_name(dev), "0000:00:01.1"))
> 		dev_info(dev, "%s %d\n", __func__, __LINE__); // this is the last reported line in netconsole
> 	if (dev->power.no_callbacks)
> 		goto no_callback;	/* Assume success. */
> 
> 	__update_runtime_status(dev, RPM_RESUMING);
> 
> 	callback = RPM_GET_CALLBACK(dev, runtime_resume);
> 
> 	dev_pm_disable_wake_irq_check(dev, false);
> 	retval = rpm_callback(callback, dev);
> 	if (retval) {
> 		__update_runtime_status(dev, RPM_SUSPENDED);
> 		pm_runtime_cancel_pending(dev);
> 		dev_pm_enable_wake_irq_check(dev, false);
> 	} else {
>  no_callback:
> 
> 
> Bert Karwatzki

The testrun is already finished the crash occured after 10h and ~700 GPP0 notifies,
the part of rpm_resume() above was monitored like this:

 skip_parent:

	if (!strcmp(dev_name(dev), "0000:00:01.1"))
		dev_info(dev, "%s %d\n", __func__, __LINE__);
	if (dev->power.no_callbacks)
		goto no_callback;	/* Assume success. */

	if (!strcmp(dev_name(dev), "0000:00:01.1"))
		dev_info(dev, "%s %d\n", __func__, __LINE__);
	__update_runtime_status(dev, RPM_RESUMING);

	if (!strcmp(dev_name(dev), "0000:00:01.1"))
		dev_info(dev, "%s %d\n", __func__, __LINE__);
	callback = RPM_GET_CALLBACK(dev, runtime_resume);

	if (!strcmp(dev_name(dev), "0000:00:01.1"))
		dev_info(dev, "%s %d callback = %px\n", __func__, __LINE__, (void *) callback);
	dev_pm_disable_wake_irq_check(dev, false);
	if (!strcmp(dev_name(dev), "0000:00:01.1"))
		dev_info(dev, "%s %d\n", __func__, __LINE__);   // This is the last reported line!
	retval = rpm_callback(callback, dev);
	if (!strcmp(dev_name(dev), "0000:00:01.1"))
		dev_info(dev, "%s %d\n", __func__, __LINE__);
	if (retval) {
		if (!strcmp(dev_name(dev), "0000:00:01.1"))
			dev_info(dev, "%s %d\n", __func__, __LINE__);
		__update_runtime_status(dev, RPM_SUSPENDED);
		pm_runtime_cancel_pending(dev);
		dev_pm_enable_wake_irq_check(dev, false);
	} else {
 no_callback:

The result is that in the case of the crash rpm_callback() didn't return, so
I'll continue the investigation in rpm_callback().

The whole calltrace is:
acpiphp_check_bridge()->pm_runtime_get_sync()->__pm_runtime_resume()->rpm_resume()->rpm_callback()

Bert Karwatzki