Vitaly Kuznetsov 8c058b0b9c x86/irq: Probe for PIC presence before allocating descs for legacy IRQs ... Commit d32932d02e ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces") brought a regression for Hyper-V Gen2 instances. These instances don't have i8259 legacy PIC but they use legacy IRQs for serial port, rtc, and acpi. With this commit included we end up with these IRQs not initialized. Earlier, there was a special workaround for legacy IRQs in mp_map_pin_to_irq() doing mp_irqdomain_map() without looking at nr_legacy_irqs() and now we fail in __irq_domain_alloc_irqs() when irq_domain_alloc_descs() returns -EEXIST. The essence of the issue seems to be that early_irq_init() calls arch_probe_nr_irqs() to figure out the number of legacy IRQs before we probe for i8259 and gets 16. Later when init_8259A() is called we switch to NULL legacy PIC and nr_legacy_irqs() starts to return 0 but we already have 16 descs allocated. Solve the issue by separating i8259 probe from init and calling it in arch_probe_nr_irqs() before we actually use nr_legacy_irqs() information. Fixes: d32932d02e ("x86/irq: Convert IOAPIC to use hierarchical irqdomain interfaces") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1446543614-3621-1-git-send-email-vkuznets@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>		2015-11-07 10:37:37 +01:00
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asm	x86/irq: Probe for PIC presence before allocating descs for legacy IRQs	2015-11-07 10:37:37 +01:00
uapi/asm	Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-11-03 21:05:40 -08:00