pinctrl-amd: Don't clear S4 wake bits at probe

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 <mario.limonciello@amd.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c
index e3128b0045d2..15a398bb3be2 100644
--- a/drivers/pinctrl/pinctrl-amd.c
+++ b/drivers/pinctrl/pinctrl-amd.c
@@ -884,8 +884,7 @@ static void amd_gpio_irq_init(struct amd_gpio *gpio_dev)
 	u32 pin_reg, mask;
 	int i;
 
-	mask = BIT(WAKE_CNTRL_OFF_S0I3) | BIT(WAKE_CNTRL_OFF_S3) |
-		BIT(WAKE_CNTRL_OFF_S4);
+	mask = BIT(WAKE_CNTRL_OFF_S0I3) | BIT(WAKE_CNTRL_OFF_S3);
 
 	for (i = 0; i < desc->npins; i++) {
 		int pin = desc->pins[i].number;