linux-kernel - Re: [Patch v4] x86, irq, PCI: Keep IRQ assignment for runtime power management

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <8823237.zCdVqYrZ5W@vostro.rjw.lan>
Date:	Sat, 30 Aug 2014 01:24:53 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	"Rafael J. Wysocki" <rafael@...nel.org>
Cc:	Jiang Liu <jiang.liu@...ux.intel.com>,
	EmanueL Czirai <amanual@...nmailbox.org>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Randy Dunlap <rdunlap@...radead.org>,
	Yinghai Lu <yinghai@...nel.org>,
	Borislav Petkov <bp@...en8.de>,
	Grant Likely <grant.likely@...aro.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Tony Luck <tony.luck@...el.com>,
	Joerg Roedel <joro@...tes.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	x86@...nel.org,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linux PCI <linux-pci@...r.kernel.org>,
	ACPI Devel Maling List <linux-acpi@...r.kernel.org>
Subject: Re: [Patch v4] x86, irq, PCI: Keep IRQ assignment for runtime power management

On Friday, August 29, 2014 04:42:34 PM Rafael J. Wysocki wrote:
> On Fri, Aug 29, 2014 at 11:26 AM, Jiang Liu <jiang.liu@...ux.intel.com> wrote:
> > Now IOAPIC driver dynamically allocates IRQ numbers for IOAPIC pins.
> > We need to keep IRQ assignment for PCI devices during runtime power
> > management, otherwise it may cause failure of device wakeups.
> >
> > Commit 3eec595235c17a7 "x86, irq, PCI: Keep IRQ assignment for PCI
> > devices during suspend/hibernation" has fixed the issue for suspend/
> > hibernation, we also need the same fix for runtime device sleep too.
> >
> > Fix: https://bugzilla.kernel.org/show_bug.cgi?id=83271
> > Reported-and-Tested-by: EmanueL Czirai <amanual@...nmailbox.org>
> > Signed-off-by: Jiang Liu <jiang.liu@...ux.intel.com>
> > ---
> >  arch/x86/include/asm/io_apic.h |    2 ++
> >  arch/x86/kernel/apic/io_apic.c |   12 ++++++++++++
> >  arch/x86/pci/intel_mid_pci.c   |    2 +-
> >  arch/x86/pci/irq.c             |    2 +-
> >  drivers/acpi/pci_irq.c         |    4 ++++
> >  5 files changed, 20 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
> > index 0aeed5ca356e..478c490f3654 100644
> > --- a/arch/x86/include/asm/io_apic.h
> > +++ b/arch/x86/include/asm/io_apic.h
> > @@ -227,6 +227,8 @@ static inline void io_apic_modify(unsigned int apic, unsigned int reg, unsigned
> >
> >  extern void io_apic_eoi(unsigned int apic, unsigned int vector);
> >
> > +extern bool mp_should_keep_irq(struct device *dev);
> > +
> >  #else  /* !CONFIG_X86_IO_APIC */
> >
> >  #define io_apic_assign_pci_irqs 0
> > diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
> > index 29290f554e79..1e9a921d9701 100644
> > --- a/arch/x86/kernel/apic/io_apic.c
> > +++ b/arch/x86/kernel/apic/io_apic.c
> > @@ -3946,6 +3946,18 @@ int mp_set_gsi_attr(u32 gsi, int trigger, int polarity, int node)
> >         return ret;
> >  }
> >
> > +bool mp_should_keep_irq(struct device *dev)
> > +{
> > +       if (dev->power.is_prepared)
> > +               return true;
> > +#ifdef CONFIG_PM_RUNTIME
> > +       if (dev->power.runtime_status == RPM_SUSPENDING)
> > +               return true;
> > +#endif
> 
> No, you can't do that.  It is racy and incorrect.

Well, maybe not.

> Please give me some time for looking into this.

So I guess the intended check is "Am I running in a suspend callback"?

Rafael

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/