Re: There are not enough CPU0 APIC IRQs while doing IRQ migration during S3

[Marc Zyngier <maz@kernel.org>]

[- Jason]

On Tue, 19 Jul 2022 06:55:21 +0100,
AceLan Kao <acelan.kao@canonical.com> wrote:
> 
> HI all,
> 
> I encountered an issue while doing S3, it shows below message and then
> failed to enter S3
> [  106.731140] CPU 31 has 116 vectors, 85 available. Cannot disable CPU
> [  106.731551] ACPI: \_PR_.C01F: Found 2 idle states
> [  106.732610] Error taking CPU31 down: -28
> [  106.732612] Non-boot CPUs are not disabled
> 
> CPU: AMD Ryzen Threadripper PRO 3955WX 16-Cores
> Kernel: v5.19-rc7
> There are 5 PCI to 4 type-c ports USB cards on the machine, and It
> wouldn't lead to the issue if only 4 cards are plugged. So, it looks
> like it can't handle 5 cards, and failed on the IRQ migration.
> 
> The workaround provided by kaiheng is to release the irq while
> suspending and request irq while resuming.
> I'm wondering do we have a better solution for this kind of issue?
> Thanks.
> 
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index edc6881c8a1b..91c79b21cb57 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -17,6 +17,7 @@
> #include <linux/slab.h>
> #include <linux/dmi.h>
> #include <linux/dma-mapping.h>
> +#include <linux/suspend.h>
> 
> #include "xhci.h"
> #include "xhci-trace.h"
> @@ -1079,6 +1080,9 @@ int xhci_suspend(struct xhci_hcd *xhci, bool do_wakeup)
>                                __func__);
>        }
> 
> +       if (pm_suspend_via_firmware())
> +               xhci_cleanup_msix(xhci);

I'm a bit clueless when it comes to the combination of x86 and xhci,
but doesn't this prevent resuming on a xhci interrupt?

	M.

-- 
Without deviation from the norm, progress is not possible.