Re: linux-next: Tree for Nov 14

[Guenter Roeck]

On 11/16/2014 08:01 AM, Guenter Roeck wrote:
> On 11/16/2014 12:24 AM, Jiang Liu wrote:
> > On 2014/11/16 14:56, Guenter Roeck wrote:
> > > On 11/15/2014 08:20 PM, Jiang Liu wrote:
> > > > On 2014/11/16 11:22, Guenter Roeck wrote:
> > > > > On 11/15/2014 06:33 PM, Jiang Liu wrote:
> > > > > > Hi Guenter,
> > > > > >       Could you please help to provide the config file and
> > > > > > error messages?
> > > > >
> > > > > Config file:
> > > > >
> > > > > https://github.com/groeck/linux-build-test/blob/master/rootfs/x86/qemu_x86_pc_nosmp_defconfig
> > > > Hi Guenter,
> > > >      Thanks for help. According to the above configuration file:
> > > > CONFIG_PCI_MSI is enabled, but CONFIG_X86_LOCAL_APIC and
> > > > CONFIG_X86_IO_APIC are both disabled. But the Kconfig for X86_LOCAL_APIC
> > > > is defined as:
> > > > config X86_LOCAL_APIC
> > > >           def_bool y
> > > >           depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
> > > > || PCI_MSI
> > > >           select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
> > > >
> > > > That means CONFIG_X86_LOCAL_APIC should be enabled if CONFIG_PCI_MSI is
> > > > enabled. So how did you generate the qemu_x86_pc_nosmp_defconfig? Are
> > > > you using an old configuration file?
> > >
> > > I took the configuration file I had for the SMP case (located in the same
> > > directory in the git repository), disabled SMP, and ran "make
> > > savedefconfig".
> > > "old" is relative in this context; I don't usually create new configuration
> > > files for each new kernel release, so, yes, you could say that the file
> > > I used is "old".
> > >
> > > CONFIG_X86_LOCAL_APIC is enabled. Keep in mind this is a configuration file
> > > created with "make savedefconfig", so default settings are not included.
> > > Correct, CONFIG_X86_IO_APIC is not enabled, but that is not really
> > > surprising
> > > since its dependencies are not met as far as I can see.
> > >
> > > Overall, I am not sure I understand what you are trying to say. X86_IO_APIC
> > > depends on X86_64 (not set) or SMP (not set) or X86_32_NON_STANDARD (not
> > > set)
> > > or X86_UP_IOAPIC (not set because it depends on X86_UP_APIC which
> > > depends on
> > > !PCI_MSI).
> > >
> > > Does that mean that I'll have to disable PCI_MSI to get x86 uniprocessor
> > > support to work after your patch ?
> > Hi Guenter,
> >     Previously, X86_IO_APIC will be enabled if PCI_MSI is enabled.
> > With my patch, x86_IO_APIC may be disabled even if PCI_MSI is enabled.
> > If X86_LOCAL_APIC/PCI_MSI are enabled and X86_IO_APIC is disabled, it
> > should work theoretically. I remember it works on my HP laptop.
> > Could you please help to check whether it solve the issue by manually
> > turning on X86_IO_APIC?
>
> I can not turn on X86_IO_APIC manually. I have to enable one of the
> following to do it.
>
>      def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
>
> Since I want to build for 32 bit, I can not enable X86_64.
> Since I want to build a uniprocessor image, I can not enable SMP.
> X86_32_NON_STANDARD depends on SMP, so I can not enable it either.
> X86_UP_IOAPIC depends on X86_UP_APIC which I can only enable by
> disabling PCI_MSI.
>
> So I disabled PCI_MSI and enabled X86_UP_IOAPIC as well as X86_IO_APIC.
> The resulting image hangs completely with no console output whatsoever.

Additional data points: After reverting your patch on top of linux-next,
everything works fine. The working configuration has CONFIG_IRQ_DOMAIN,
CONFIG_X86_IO_APIC, CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS, and
CONFIG_ACPI_HOTPLUG_IOAPIC enabled. The non-working configuration
(with your patch applied) has all those disabled.

Guenter

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