tree 8311a41b3eef9c2758d342238ec78a6fc14d3567
parent 5e3bf215f4f2efc0af89e6dbc5da789744aeb5d7
author Jiang Liu <jiang.liu@linux.intel.com> 1407478071 +0800
committer Thomas Gleixner <tglx@linutronix.de> 1407489285 +0200

x86, irq, PCI: Keep IRQ assignment for PCI devices during suspend/hibernation

Now IOAPIC driver dynamically allocates IRQ numbers for IOAPIC pins.
We need to keep IRQ assignment for PCI devices during suspend/hibernation,
otherwise it may cause failure of suspend/hibernation due to:
1) Device driver calls pci_enable_device() to allocate an IRQ number
   and register interrupt handler on the returned IRQ.
2) Device driver's suspend callback calls pci_disable_device() and
   release assigned IRQ in turn.
3) Device driver's resume callback calls pci_enable_device() to
   allocate IRQ number again. A different IRQ number may be assigned
   by IOAPIC driver this time.
4) Now the hardware delivers interrupt to the new IRQ but interrupt
   handler is still registered against the old IRQ, so it breaks
   suspend/hibernation.

To fix this issue, we keep IRQ assignment during suspend/hibernation.
Flag pci_dev.dev.power.is_prepared is used to detect that
pci_disable_device() is called during suspend/hibernation.

Reported-and-Tested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Link: http://lkml.kernel.org/r/1407478071-29399-1-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>