[PATCH] PCI: Use pci_reset_bus() in quirk_reset_lenovo_thinkpad_50_nvgpu()

[Lyude Paul]

Since quirk_nvidia_hda() was added there's now two nvidia device
functions on any laptops with nvidia GPUs: the HDA controller, and the
GPU itself. Unfortunately this has the sideaffect of breaking
quirk_reset_lenovo_thinkpad_50_nvgpu() since pci_reset_function() was
using pci_parent_bus_reset() to reset the GPU's respective PCI bus, and
pci_parent_bus_reset() does not work on busses which have more then a
single device function present.

So, fix this by simply calling pci_reset_bus() instead which properly
resets the GPU bus and all device functions under it, including both the
GPU and the HDA controller.

Fixes: b516ea586d71 ("PCI: Enable NVIDIA HDA controllers")
Cc: Lukas Wunner <lukas@xxxxxxxxx>
Cc: Daniel Drake <drake@xxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Aaron Plattner <aplattner@xxxxxxxxxx>
Cc: Peter Wu <peter@xxxxxxxxxxxxx>
Cc: Ilia Mirkin <imirkin@xxxxxxxxxxxx>
Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: Maik Freudenberg <hhfeuer@xxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
 drivers/pci/quirks.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 208aacf39329..44c4ae1abd00 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5256,7 +5256,7 @@ static void quirk_reset_lenovo_thinkpad_p50_nvgpu(struct pci_dev *pdev)
 	 */
 	if (ioread32(map + 0x2240c) & 0x2) {
 		pci_info(pdev, FW_BUG "GPU left initialized by EFI, resetting\n");
-		ret = pci_reset_function(pdev);
+		ret = pci_reset_bus(pdev);
 		if (ret < 0)
 			pci_err(pdev, "Failed to reset GPU: %d\n", ret);
 	}
-- 
2.21.0