[PATCH v2] ACPI: x86: Disable wakeup on MSI MS-1592 and MS-1594 dGPU root port

[Victor Carreras]

On MSI Summit E16 Flip A12UCT (motherboard MS-1592, BIOS E1592IMS.111)
and MSI Prestige 16 Studio A13VE / Summit E16 Flip A13VET (motherboard
MS-1594, BIOS E1594IMS.115), the I2C touchpad (ELAN0305:00, 04F3:31FD)
permanently stops generating interrupts as soon as the discrete NVIDIA
GPU (0000:01:00.0) and its parent PCIe Root Port (0000:00:06.0,
\_SB.PC00.PEG0) enter D3cold.

In the platform's SSDT (MSI_NB / AdlP_Rvp), \_SB.PC00.PEG0 sets its wake
GPIO (WAKG) from the BIOS NVS variable P1WP, which erroneously points to
GPP_A20 (INTC1055:00 pin 62) -- the GPIO interrupt line wired to the
touchpad.

During boot, \_SB.PC00.PEG0.PON() calls \_SB.SHPO(WAKG, One), setting
PAD_CFG0_GPP_A20.GPIROUTSCI = 0 and HostSwOwn = 1 so the OS GPIO driver
owns the pin. However, when the root port runtime-suspends to D3cold,
Linux enables ACPI wakeup via \_SB.PC00.PEG0._DSW(1, 0, 3), which sets
WKEN = 1. Subsequent evaluation of \_SB.PC00.PEG0.PXP._OFF -> POFF()
executes:

  If (CondRefOf (WAKG))
  {
      If (((WAKG != Zero) && WKEN))
      {
          \_SB.SHPO (WAKG, Zero)
      }
  }

This switches GPP_A20 ownership to ACPI GPE mode (HostSwOwn = 0,
GPIROUTSCI = 1), silencing the touchpad interrupt until the dGPU wakes
back up to D0. Under Windows, _DSW is not armed for S0 D3cold on this
root port, leaving WKEN = 0 so POFF() powers off the dGPU (\PIN.OFF(PWRG))
without touching GPP_A20.

Add a PCI quirk in drivers/acpi/x86/utils.c for boards MS-1592 and
MS-1594 on root port 0000:00:06.0 (8086:464d on 12th Gen Alder Lake-P
and 8086:a74d on 13th Gen Raptor Lake-P/H) to disable wakeup capability.
This keeps WKEN = 0 so the root port and dGPU still reach D3cold
normally while leaving GPP_A20 owned by the GPIO driver.

Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220725
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Victor Carreras <vicajilau@xxxxxxxxx>
---
Changes in v2:
- Move the quirk from drivers/pci/quirks.c to drivers/acpi/x86/utils.c
  as it is x86-specific (Lukas Wunner).
- Drop clearing adev->wakeup.flags.valid in the final fixup so ACPI
  power resource dependent tracking between pci_acpi_setup() and
  pci_acpi_cleanup() remains balanced.
- Link to v1: https://lore.kernel.org/r/179272791966.20251.3697951431087014523@xxxxxxxxx

 drivers/acpi/x86/utils.c | 47 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/drivers/acpi/x86/utils.c b/drivers/acpi/x86/utils.c
index 4189516..84a6ca7 100644
--- a/drivers/acpi/x86/utils.c
+++ b/drivers/acpi/x86/utils.c
@@ -665,3 +665,50 @@ void __init acpi_proc_quirk_mwait_check(void)
 	 */
 	dmi_check_system(acpi_proc_quirk_mwait_dmi_table);
 }
+
+/*
+ * On MSI Summit E16 Flip A12UCT (board MS-1592) and MSI Prestige 16 Studio
+ * A13VE / Summit E16 Flip A13VET (board MS-1594), the BIOS SSDT (MSI_NB /
+ * AdlP_Rvp) assigns the touchpad's GPIO interrupt pin (GPP_A20) as the PCIe
+ * wake GPIO (WAKG / P1WP) for the dGPU root port (\_SB.PC00.PEG0, 0000:00:06.0).
+ *
+ * When ACPI wakeup is armed on this root port via _DSW (setting WKEN = 1),
+ * subsequent D3cold transitions (\_SB.PC00.PEG0.PXP._OFF -> POFF) call
+ * \_SB.SHPO(WAKG, Zero), switching GPP_A20 ownership from GPIO driver mode
+ * to ACPI GPE mode and permanently freezing the I2C touchpad (ELAN0305:00).
+ *
+ * Disable wakeup on this root port so _DSW is not armed and WKEN remains zero
+ * during D3cold transitions.
+ */
+static const struct dmi_system_id msi_peg0_no_wakeup_dmi_table[] = {
+	{
+		.ident = "MSI MS-1592",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Micro-Star International Co., Ltd."),
+			DMI_MATCH(DMI_BOARD_NAME, "MS-1592"),
+		},
+	},
+	{
+		.ident = "MSI MS-1594",
+		.matches = {
+			DMI_MATCH(DMI_BOARD_VENDOR, "Micro-Star International Co., Ltd."),
+			DMI_MATCH(DMI_BOARD_NAME, "MS-1594"),
+		},
+	},
+	{}
+};
+
+static void quirk_msi_peg0_no_wakeup(struct pci_dev *dev)
+{
+	if (pci_dev_id(dev) != PCI_DEVID(0, PCI_DEVFN(6, 0)))
+		return;
+
+	if (!dmi_check_system(msi_peg0_no_wakeup_dmi_table))
+		return;
+
+	pci_info(dev, FW_BUG "Disabling ACPI wakeup to avoid touchpad GPIO (GPP_A20) takeover in D3cold\n");
+	device_wakeup_disable(&dev->dev);
+	device_set_wakeup_capable(&dev->dev, false);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x464d, quirk_msi_peg0_no_wakeup);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0xa74d, quirk_msi_peg0_no_wakeup);
-- 
2.55.0