[PATCH] powerpc/pseries/msi: Avoid reading PCI device registers in reduced power states

[Madhavan Srinivasan]

On Wed, 05 Mar 2025 14:32:36 +0530, Gautam Menghani wrote:
> When a system is being suspended to RAM, the PCI devices are also
> suspended and the PPC code ends up calling pseries_msi_compose_msg() and
> this triggers the BUG_ON() in __pci_read_msi_msg() because the device at
> this point is in reduced power state. In reduced power state, the memory
> mapped registers of the PCI device are not accessible.
> 
> To replicate the bug:
> 1. Make sure deep sleep is selected
> 	# cat /sys/power/mem_sleep
> 	s2idle [deep]
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/pseries/msi: Avoid reading PCI device registers in reduced power states
      https://git.kernel.org/powerpc/c/9cc0eafd28c7faef300822992bb08d79cab2a36c

Thanks