Re: [PATCH v3 3/3] PCI: dwc: Enable MSI affinity support

From: Brian Norris

Date: Fri May 22 2026 - 20:07:48 EST


(Updating Radu's email; dropping another bouncing email)

On Fri, May 22, 2026 at 01:27:43PM -0700, Brian Norris wrote:
> I'll see if I can learn anything more here on my own, but I figured I'd
> report it in case you have any thoughts or leads I should investigate.

In an hour or two of poking, all I've learned so far is that the problem
also seems to go away if I:

(a) add a few dump_stack() and other noisy logs to a few key places (for
now, __pci_write_msi_msg(), pci_power_up() failures, and
irq_chip_redirect_set_affinity() -- I think __pci_write_msi_msg()
was the most significant, possibly because it produced the most log
text) and

(b) leave a 115200 baud UART kernel console running.

(This is on a sample size of 20+ suspend cycles, whereas previous
bisection would fail 100%.)

It then reappers when I quiet the kernel logging a bit with `dmesg -n3`.

I think that simply tells me that there's some timing issue or race
condition involved.

Brian