usb: dwc3: gadget: Set speed only up to the max supported

The setting of the device speed should be limited by the device's
maximum_speed. Check and prevent the driver from attempting to configure
higher than the maximum_speed.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/4fae4a9ebb60464d64d8b8f6fdfc2777a2206a69.1611106162.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0aa89e7..9acf515 100644 (file)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2064,9 +2064,14 @@ static void __dwc3_gadget_set_ssp_rate(struct dwc3 *dwc)
 
 static void __dwc3_gadget_set_speed(struct dwc3 *dwc)
 {
+       enum usb_device_speed   speed;
        u32                     reg;
 
-       if (dwc->gadget_max_speed == USB_SPEED_SUPER_PLUS &&
+       speed = dwc->gadget_max_speed;
+       if (speed > dwc->maximum_speed)
+               speed = dwc->maximum_speed;
+
+       if (speed == USB_SPEED_SUPER_PLUS &&
            DWC3_IP_IS(DWC32)) {
                __dwc3_gadget_set_ssp_rate(dwc);
                return;
@@ -2092,7 +2097,7 @@ static void __dwc3_gadget_set_speed(struct dwc3 *dwc)
            !dwc->dis_metastability_quirk) {
                reg |= DWC3_DCFG_SUPERSPEED;
        } else {
-               switch (dwc->gadget_max_speed) {
+               switch (speed) {
                case USB_SPEED_LOW:
                        reg |= DWC3_DCFG_LOWSPEED;
                        break;
@@ -2112,7 +2117,7 @@ static void __dwc3_gadget_set_speed(struct dwc3 *dwc)
                                reg |= DWC3_DCFG_SUPERSPEED_PLUS;
                        break;
                default:
-                       dev_err(dwc->dev, "invalid speed (%d)\n", dwc->gadget_max_speed);
+                       dev_err(dwc->dev, "invalid speed (%d)\n", speed);
 
                        if (DWC3_IP_IS(DWC3))
                                reg |= DWC3_DCFG_SUPERSPEED;
@@ -2122,8 +2127,8 @@ static void __dwc3_gadget_set_speed(struct dwc3 *dwc)
        }
 
        if (DWC3_IP_IS(DWC32) &&
-           dwc->gadget_max_speed > USB_SPEED_UNKNOWN &&
-           dwc->gadget_max_speed < USB_SPEED_SUPER_PLUS)
+           speed > USB_SPEED_UNKNOWN &&
+           speed < USB_SPEED_SUPER_PLUS)
                reg &= ~DWC3_DCFG_NUMLANES(~0);
 
        dwc3_writel(dwc->regs, DWC3_DCFG, reg);