Re: [BUG?] Interrupts enabled after xen_acpi_processor_resume+0x0/0x34 [xen_acpi_processor]

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Mon, Feb 03, 2014 at 09:14:29AM -0500, Konrad Rzeszutek Wilk wrote:
> On Mon, Feb 03, 2014 at 11:12:16AM +0100, Stanislaw Gruszka wrote:
> > On Fri, Jan 31, 2014 at 11:01:40AM -0500, Konrad Rzeszutek Wilk wrote:
> > > Perhaps by using 'subsys_system_register' and stick it there?
> > 
> > This will not call ->resume callback as it is only called for
> > devices, so additional dummy device is needed, for example:
> > 
> > struct device xap_dev = {
> >         .init_name = "xen-acpi-processor-dev",
> >         .bus = &xap_bus,
> > };
> > ...
> > subsys_system_register(&xap_bus, NULL);
> > device_register(&xap_dev);
> > 
> > But I'm not sure if that is good solution. It crate some not necessery
> > sysfs directories and files. Additionaly it can restore CPU C-states
> > after some other drivers resume, which prehaps require proper C-states.
> 
> Yes.
> > 
> > Hence maybe adding direct notify from xen core resume will be better
> > idea (proposed patch below). Plese let me know what you think, I'll
> > provide solution which you choose to bug reporters for testing.
> 
> Let me think about it for a day or so.

Sorry for the delay. I think this is fine.
> 
> Thanks!
> > 
> > Thanks
> > Stanislaw
> > 
> > diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
> > index 624e8dc..96e4173 100644
> > --- a/drivers/xen/manage.c
> > +++ b/drivers/xen/manage.c
> > @@ -13,6 +13,7 @@
> >  #include <linux/freezer.h>
> >  #include <linux/syscore_ops.h>
> >  #include <linux/export.h>
> > +#include <linux/notifier.h>
> >  
> >  #include <xen/xen.h>
> >  #include <xen/xenbus.h>
> > @@ -46,6 +47,20 @@ struct suspend_info {
> >  	void (*post)(int cancelled);
> >  };
> >  
> > +static RAW_NOTIFIER_HEAD(xen_resume_notifier);
> > +
> > +void xen_resume_notifier_register(struct notifier_block *nb)
> > +{
> > +	raw_notifier_chain_register(&xen_resume_notifier, nb);
> > +}
> > +EXPORT_SYMBOL_GPL(xen_resume_notifier_register);
> > +
> > +void xen_resume_notifier_unregister(struct notifier_block *nb)
> > +{
> > +	raw_notifier_chain_unregister(&xen_resume_notifier, nb);
> > +}
> > +EXPORT_SYMBOL_GPL(xen_resume_notifier_unregister);
> > +
> >  #ifdef CONFIG_HIBERNATE_CALLBACKS
> >  static void xen_hvm_post_suspend(int cancelled)
> >  {
> > @@ -152,6 +167,8 @@ static void do_suspend(void)
> >  
> >  	err = stop_machine(xen_suspend, &si, cpumask_of(0));
> >  
> > +	raw_notifier_call_chain(&xen_resume_notifier, 0, NULL);
> > +
> >  	dpm_resume_start(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
> >  
> >  	if (err) {
> > diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
> > index 7231859..82358d1 100644
> > --- a/drivers/xen/xen-acpi-processor.c
> > +++ b/drivers/xen/xen-acpi-processor.c
> > @@ -27,10 +27,10 @@
> >  #include <linux/init.h>
> >  #include <linux/module.h>
> >  #include <linux/types.h>
> > -#include <linux/syscore_ops.h>
> >  #include <linux/acpi.h>
> >  #include <acpi/processor.h>
> >  #include <xen/xen.h>
> > +#include <xen/xen-ops.h>
> >  #include <xen/interface/platform.h>
> >  #include <asm/xen/hypercall.h>
> >  
> > @@ -495,14 +495,15 @@ static int xen_upload_processor_pm_data(void)
> >  	return rc;
> >  }
> >  
> > -static void xen_acpi_processor_resume(void)
> > +static int xen_acpi_processor_resume(struct notifier_block *nb,
> > +				     unsigned long action, void *data)
> >  {
> >  	bitmap_zero(acpi_ids_done, nr_acpi_bits);
> > -	xen_upload_processor_pm_data();
> > +	return xen_upload_processor_pm_data();
> >  }
> >  
> > -static struct syscore_ops xap_syscore_ops = {
> > -	.resume	= xen_acpi_processor_resume,
> > +struct notifier_block xen_acpi_processor_resume_nb = {
> > +	.notifier_call = xen_acpi_processor_resume,
> >  };
> >  
> >  static int __init xen_acpi_processor_init(void)
> > @@ -555,7 +556,7 @@ static int __init xen_acpi_processor_init(void)
> >  	if (rc)
> >  		goto err_unregister;
> >  
> > -	register_syscore_ops(&xap_syscore_ops);
> > +	xen_resume_notifier_register(&xen_acpi_processor_resume_nb);
> >  
> >  	return 0;
> >  err_unregister:
> > @@ -574,7 +575,7 @@ static void __exit xen_acpi_processor_exit(void)
> >  {
> >  	int i;
> >  
> > -	unregister_syscore_ops(&xap_syscore_ops);
> > +	xen_resume_notifier_unregister(&xen_acpi_processor_resume_nb);
> >  	kfree(acpi_ids_done);
> >  	kfree(acpi_id_present);
> >  	kfree(acpi_id_cst_present);
> > diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
> > index fb2ea8f..6412358 100644
> > --- a/include/xen/xen-ops.h
> > +++ b/include/xen/xen-ops.h
> > @@ -16,6 +16,9 @@ void xen_mm_unpin_all(void);
> >  void xen_timer_resume(void);
> >  void xen_arch_resume(void);
> >  
> > +void xen_resume_notifier_register(struct notifier_block *nb);
> > +void xen_resume_notifier_unregister(struct notifier_block *nb);
> > +
> >  int xen_setup_shutdown_event(void);
> >  
> >  extern unsigned long *xen_contiguous_bitmap;