[v5,12/12] usb: dwc3: gadget: Set speed only up to the max supported

Commit Message

Thinh Nguyen Sept. 25, 2020, 2:44 a.m. UTC

The setting of device speed should be limited by the device's
maximum_speed. This patch adds a check and prevent the driver from
attempting to configure higher than the maximum_speed.

Signed-off-by: Thinh Nguyen <[e-mail]>
---
Changes in v5:
- Rebase on Felipe's testing/next branch
- Changed Signed-off-by email to match From: email header
Changes in v4:
- None
Changes in v3:
- None
Changes in v2:
- None

 drivers/usb/dwc3/gadget.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Patch

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 66b4ea8473a6..b90df29cc23f 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2327,6 +2327,7 @@  static void dwc3_gadget_set_speed(struct usb_gadget *g,
 				  enum usb_device_speed speed)
 {
 	struct dwc3		*dwc = gadget_to_dwc(g);
+	enum usb_device_speed	selected_speed = speed;
 	unsigned long		flags;
 	u32			reg;
 
@@ -2351,7 +2352,10 @@  static void dwc3_gadget_set_speed(struct usb_gadget *g,
 	    !dwc->dis_metastability_quirk) {
 		reg |= DWC3_DCFG_SUPERSPEED;
 	} else {
-		switch (speed) {
+		if (speed > dwc->maximum_speed)
+			selected_speed = dwc->maximum_speed;
+
+		switch (selected_speed) {
 		case USB_SPEED_LOW:
 			reg |= DWC3_DCFG_LOWSPEED;
 			break;
@@ -2371,7 +2375,8 @@  static void dwc3_gadget_set_speed(struct usb_gadget *g,
 				reg |= DWC3_DCFG_SUPERSPEED_PLUS;
 			break;
 		default:
-			dev_err(dwc->dev, "invalid speed (%d)\n", speed);
+			dev_err(dwc->dev, "invalid speed (%d)\n",
+				selected_speed);
 
 			if (DWC3_IP_IS(DWC3))
 				reg |= DWC3_DCFG_SUPERSPEED;
@@ -2380,7 +2385,7 @@  static void dwc3_gadget_set_speed(struct usb_gadget *g,
 		}
 	}
 
-	if (DWC3_IP_IS(DWC32) && speed < USB_SPEED_SUPER_PLUS)
+	if (DWC3_IP_IS(DWC32) && selected_speed < USB_SPEED_SUPER_PLUS)
 		reg &= ~DWC3_DCFG_NUMLANES(~0);
 
 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);