Re: [RFC v1 1/2] x86: kconfig: simplify enabling [IO]APIC for PCI_MSI

["Luis R. Rodriguez" <mcgrof@suse.com>]

On Tue, Mar 10, 2015 at 05:49:10PM -0700, David Rientjes wrote:
> On Tue, 10 Mar 2015, Luis R. Rodriguez wrote:
> 
> > diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt
> > index 0d920d5..7306d2c 100644
> > --- a/Documentation/PCI/MSI-HOWTO.txt
> > +++ b/Documentation/PCI/MSI-HOWTO.txt
> > @@ -71,10 +71,7 @@ will simply fail and the device will continue to use pin-based interrupts.
> >  4.1 Include kernel support for MSIs
> >  
> >  To support MSI or MSI-X, the kernel must be built with the CONFIG_PCI_MSI
> > -option enabled.  This option is only available on some architectures,
> > -and it may depend on some other options also being set.  For example,
> > -on x86, you must also enable X86_UP_APIC or SMP in order to see the
> > -CONFIG_PCI_MSI option.
> > +option enabled.  This option is only available on some architectures.
> >  
> >  4.2 Using MSI
> >  
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index d038475..0ecdeb1 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -902,10 +902,6 @@ config X86_UP_APIC
> >  	  performance counters), and the NMI watchdog which detects hard
> >  	  lockups.
> >  
> > -config X86_UP_APIC_MSI
> > -	def_bool y
> > -	select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
> > -
> >  config X86_UP_IOAPIC
> >  	bool "IO-APIC support on uniprocessors"
> >  	depends on X86_UP_APIC
> > @@ -924,7 +920,7 @@ config X86_LOCAL_APIC
> >  	select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
> >  
> >  config X86_IO_APIC
> > -	def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
> > +	def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
> >  	depends on X86_LOCAL_APIC
> >  	select IRQ_DOMAIN
> >  
> > diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> > index 7a8f1c5..01370c0 100644
> > --- a/drivers/pci/Kconfig
> > +++ b/drivers/pci/Kconfig
> > @@ -5,6 +5,8 @@ config PCI_MSI
> >  	bool "Message Signaled Interrupts (MSI and MSI-X)"
> >  	depends on PCI
> >  	select GENERIC_MSI_IRQ
> > +	select X86_LOCAL_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD
> > +	select X86_IO_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD
> >  	help
> >  	   This allows device drivers to enable MSI (Message Signaled
> >  	   Interrupts).  Message Signaled Interrupts enable a device to
> 
> and I think I prefer the simplification done there over the 
> additional "select"s for PCI_MSI.

OK found a way to address that which makes it even easier to read.

 Luis