usb: dwc3: gadget: Fix ssp speed setting

Fix a couple of issues with setting the gadget's speed for DWC_usb32 IP. We should not notice this issue with other IPs.

Thinh Nguyen (2):
usb: dwc3: gadget: Set gadget_max_speed when set ssp_rate
usb: dwc3: gadget: Use max speed if unspecified

 drivers/usb/dwc3/gadget.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

base-commit: 7f6f181b3e2c4d08f5d693eebe7901a28fab8666

2.28.0

Set the dwc->gadget_max_speed to SuperSpeed Plus if the user sets the ssp_rate. The udc_set_ssp_rate() is intended for setting the gadget's speed to SuperSpeed Plus at the specified rate.

---
 drivers/usb/dwc3/gadget.c | 1 +
 1 file changed, 1 insertion(+)

index aebcf8ec0716..53696c4bed0a 100644
@@ -2523,6 +2523,7 @@ static void dwc3_gadget_set_ssp_rate(struct usb_gadget *g,
 	unsigned long		flags;
 
 	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->gadget_max_speed = USB_SPEED_SUPER_PLUS;
 	dwc->gadget_ssp_rate = rate;
 	spin_unlock_irqrestore(&dwc->lock, flags);
 }

2.28.0

If the gadget driver doesn't specify a max_speed, then use the controller's maximum supported speed as default. For DWC_usb32 IP, the gadget's speed maybe limited to gen2x1 rate only if the driver's max_speed is unknown. This scenario should not occur with the current implementation since the default gadget driver's max_speed should always be specified. However, to make the driver more robust and help with readability, let's cover all the scenarios in __dwc3_gadget_set_speed().

---
 drivers/usb/dwc3/gadget.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 53696c4bed0a..a04a9757f541 100644
@@ -2083,7 +2083,7 @@ static void __dwc3_gadget_set_speed(struct dwc3 *dwc)
 	u32			reg;
 
 	speed = dwc->gadget_max_speed;
-	if (speed > dwc->maximum_speed)
+	if (speed == USB_SPEED_UNKNOWN || speed > dwc->maximum_speed)
 		speed = dwc->maximum_speed;
 
 	if (speed == USB_SPEED_SUPER_PLUS &&

2.28.0