genirq/msi: Silence 'set affinity failed' warning

Various PCI controllers that mux MSIs onto a single IRQ line produce these
"IRQ%d: set affinity failed" warnings when entering suspend. This has been
discussed before [1] [2] and an example test case is included at the end of
this commit message.

Controller drivers that create MSI IRQ domain with
MSI_FLAG_USE_DEF_CHIP_OPS and do not override the .irq_set_affinity()
irqchip callback get assigned the default msi_domain_set_affinity()
callback. That is not desired on controllers where it is not possible to
set affinity of each MSI IRQ line to a specific CPU core due to hardware
limitation.

Introduce flag MSI_FLAG_NO_AFFINITY, which keeps .irq_set_affinity() unset
if the controller driver did not assign it.  This way, migrate_one_irq()
can exit right away, without printing the warning. The .irq_set_affinity()
implementations which only return -EINVAL can be removed from multiple
controller drivers.

  $ grep 25 /proc/interrupts
   25:   0 0 0 0 0 0 0 0   PCIe MSI   0   Edge   PCIe PME

  $ echo core > /sys/power/pm_test ; echo mem > /sys/power/state
  ...
  Disabling non-boot CPUs ...
  IRQ25: set affinity failed(-22). <---------- This is being silenced here
  psci: CPU7 killed (polled 4 ms)
  ...

[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/all/[email protected]/

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Marek Vasut <[email protected]>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Manivannan Sadhasivam <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>

0 files changed, 0 insertions, 0 deletions