[PATCH] usb/host/pci-quirks: Only reset USB bus on NVIDIA devices

From: Paul Menzel
Date: Sun Jul 01 2018 - 17:23:13 EST

Currently, on the AMD board Asus F2A85-M Pro there is a 100 ms delay as
the USB bus of each of the two OHCI PCI devices is reset. As a 50 ms
delay is done per the USB specification.

Commit c6187597 (OHCI: final fix for NVIDIA problems (I hope))
unconditionally does the bus reset for
all chipsets, while it was only doen for NVIDIA chipsets before.

As it should not be needed for non-NVIDIA chipsets, only do the reset
for Nvidia devices.

Tested on Asus F2A85-M PRO and ASRock E350M1. The USB keyboard works and
the LUKS passphrase can be e

Signed-off-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
drivers/usb/host/pci-quirks.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 3625a5c1a41b..f6b1a9bbe301 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -784,7 +784,7 @@ static void quirk_usb_handoff_ohci(struct pci_dev *pdev)
writel((u32) ~0, base + OHCI_INTRDISABLE);

/* Reset the USB bus, if the controller isn't already in RESET */
- if (control & OHCI_HCFS) {
+ if ((pdev->vendor == PCI_VENDOR_ID_NVIDIA) && (control & OHCI_HCFS)) {
/* Go into RESET, preserving RWC (and possibly IR) */
writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
readl(base + OHCI_CONTROL);