1 files changed, 58 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 6f34e17c98f4..98c9c47f9d0e 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5137,3 +5137,61 @@ SWITCHTEC_QUIRK(0x8573);  /* PFXI 48XG3 */
 SWITCHTEC_QUIRK(0x8574);  /* PFXI 64XG3 */
 SWITCHTEC_QUIRK(0x8575);  /* PFXI 80XG3 */
 SWITCHTEC_QUIRK(0x8576);  /* PFXI 96XG3 */
+
+/*
+ * On Lenovo Thinkpad P50 SKUs with a Nvidia Quadro M1000M, the BIOS does
+ * not always reset the secondary Nvidia GPU between reboots if the system
+ * is configured to use Hybrid Graphics mode.  This results in the GPU
+ * being left in whatever state it was in during the *previous* boot, which
+ * causes spurious interrupts from the GPU, which in turn causes us to
+ * disable the wrong IRQ and end up breaking the touchpad.  Unsurprisingly,
+ * this also completely breaks nouveau.
+ *
+ * Luckily, it seems a simple reset of the Nvidia GPU brings it back to a
+ * clean state and fixes all these issues.
+ *
+ * When the machine is configured in Dedicated display mode, the issue
+ * doesn't occur.  Fortunately the GPU advertises NoReset+ when in this
+ * mode, so we can detect that and avoid resetting it.
+ */
+static void quirk_reset_lenovo_thinkpad_p50_nvgpu(struct pci_dev *pdev)
+{
+	void __iomem *map;
+	int ret;
+
+	if (pdev->subsystem_vendor != PCI_VENDOR_ID_LENOVO ||
+	    pdev->subsystem_device != 0x222e ||
+	    !pdev->reset_fn)
+		return;
+
+	if (pci_enable_device_mem(pdev))
+		return;
+
+	/*
+	 * Based on nvkm_device_ctor() in
+	 * drivers/gpu/drm/nouveau/nvkm/engine/device/base.c
+	 */
+	map = pci_iomap(pdev, 0, 0x23000);
+	if (!map) {
+		pci_err(pdev, "Can't map MMIO space\n");
+		goto out_disable;
+	}
+
+	/*
+	 * Make sure the GPU looks like it's been POSTed before resetting
+	 * it.
+	 */
+	if (ioread32(map + 0x2240c) & 0x2) {
+		pci_info(pdev, FW_BUG "GPU left initialized by EFI, resetting\n");
+		ret = pci_reset_function(pdev);
+		if (ret < 0)
+			pci_err(pdev, "Failed to reset GPU: %d\n", ret);
+	}
+
+	iounmap(map);
+out_disable:
+	pci_disable_device(pdev);
+}
+DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, 0x13b1,
+			      PCI_CLASS_DISPLAY_VGA, 8,
+			      quirk_reset_lenovo_thinkpad_p50_nvgpu);