Re: [PATCH] pinctrl-amd: Don't clear S4 wake bits at probe

On Mon, Jul 20, 2026 at 6:29 PM Mario Limonciello
<[email protected]> wrote:

> commit 6bc3462a0f5e ("pinctrl: amd: Mask wake bits on probe again")
> introduced a regression where Wake-on-LAN no longer works after suspend
> or shutdown on some AMD platforms.
>
> Firmware-programmed S4 wake bits for devices like PCIe NICs using PCI
> PME are cleared at probe, but nothing restores them. Unlike S0i3/S3 wake
> sources that use enable_irq_wake() -> amd_gpio_irq_set_wake(), PCIe PME
> does not use GPIO IRQ infrastructure and relies on firmware configuration.
>
> The original intent of commit 6bc3462a0f5e ("pinctrl: amd: Mask wake
> bits on probe again") was to clear spurious wake bits left by firmware
> to prevent unwanted wakeups. However, S4 wake bits are used for
> hardware-level wake sources like WoL that bypass the kernel's IRQ wake
> API.
>
> Fix by preserving S4 wake bits at probe and only clearing S0i3/S3 bits:
> - Firmware-configured S4 wake sources (WoL) continue working
> - Kernel maintains control of S3/S0i3 wake policy via set_wake()
> - S3-only wake sources work correctly per commit f31f33dbb3ba ("pinctrl:
>   amd: Take suspend type into consideration which pins are non-wake")
>
> The trade-off is that firmware-programmed spurious S4 wake bits remain
> set, but this is less problematic than breaking WoL.
>
> Fixes: 6bc3462a0f5e ("pinctrl: amd: Mask wake bits on probe again")
> Signed-off-by: Mario Limonciello <[email protected]>

Patch applied for fixes, thanks for always fixing these
issues Mario!

Yours,
Linus Walleij