From 46248cbac7ca6e688ebe5be29344239c78a884a7 Mon Sep 17 00:00:00 2001
From: Maximilian Luz <luzmaximilian@gmail.com>
Date: Sun, 19 Feb 2023 22:12:24 +0100
Subject: [PATCH] PCI: Add quirk to prevent calling shutdown method

Work around buggy EFI firmware: On some Microsoft Surface devices
(Surface Pro 9 and Surface Laptop 5) the EFI ResetSystem call with
EFI_RESET_SHUTDOWN doesn't function properly. Instead of shutting the
system down, it returns and the system stays on.

It turns out that this only happens after PCI shutdown callbacks ran for
specific devices. Excluding those devices from the shutdown process
makes the ResetSystem call work as expected.

TODO: Maybe we can find a better way or the root cause of this?

Not-Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Patchset: surface-shutdown
---
 drivers/pci/pci-driver.c |  3 +++
 drivers/pci/quirks.c     | 36 ++++++++++++++++++++++++++++++++++++
 include/linux/pci.h      |  1 +
 3 files changed, 40 insertions(+)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 66e3bea7dc1a..6c30e1f649cd 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -505,6 +505,9 @@ static void pci_device_shutdown(struct device *dev)
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	struct pci_driver *drv = pci_dev->driver;
 
+	if (pci_dev->no_shutdown)
+		return;
+
 	pm_runtime_resume(dev);
 
 	if (drv && drv->shutdown)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 6e29f2b39dce..2198c761c737 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -6341,3 +6341,39 @@ static void pci_mask_replay_timer_timeout(struct pci_dev *pdev)
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_GLI, 0x9750, pci_mask_replay_timer_timeout);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_GLI, 0x9755, pci_mask_replay_timer_timeout);
 #endif
+
+static const struct dmi_system_id no_shutdown_dmi_table[] = {
+	/*
+	 * Systems on which some devices should not be touched during shutdown.
+	 */
+	{
+		.ident = "Microsoft Surface Pro 9",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Surface Pro 9"),
+		},
+	},
+	{
+		.ident = "Microsoft Surface Laptop 5",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Surface Laptop 5"),
+		},
+	},
+	{}
+};
+
+static void quirk_no_shutdown(struct pci_dev *dev)
+{
+	if (!dmi_check_system(no_shutdown_dmi_table))
+		return;
+
+	dev->no_shutdown = 1;
+	pci_info(dev, "disabling shutdown ops for [%04x:%04x]\n",
+		 dev->vendor, dev->device);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x461e, quirk_no_shutdown);  // Thunderbolt 4 USB Controller
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x461f, quirk_no_shutdown);  // Thunderbolt 4 PCI Express Root Port
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x462f, quirk_no_shutdown);  // Thunderbolt 4 PCI Express Root Port
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x466d, quirk_no_shutdown);  // Thunderbolt 4 NHI
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x46a8, quirk_no_shutdown);  // GPU
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0b03176f07aa..c526db8b69d2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -486,6 +486,7 @@ struct pci_dev {
 	unsigned int	rom_bar_overlap:1;	/* ROM BAR disable broken */
 	unsigned int	rom_attr_enabled:1;	/* Display of ROM attribute enabled? */
 	unsigned int	non_mappable_bars:1;	/* BARs can't be mapped to user-space  */
+	unsigned int	no_shutdown:1;		/* Do not touch device on shutdown */
 	pci_dev_flags_t dev_flags;
 	atomic_t	enable_cnt;	/* pci_enable_device has been called */
 
-- 
2.51.0

