[PATCH] usb: cdns3: gadget: Fix g_audio use case when connected to Super-Speed host

Roger Quadros
2019-10-29T15:15:34Z

Take into account gadget driver's speed limit when programming
controller speed.

Signed-off-by: Roger Quadros <rogerq@ti.com>
---
Hi Greg,

Please apply this for -rc.
Without this, g_audio is broken on cdns3 USB controller is
connected to a Super-Speed host.

cheers,
-roger

drivers/usb/cdns3/gadget.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
index 40dad4e8d0dc..1c724c20d468 100644
--- a/drivers/usb/cdns3/gadget.c
+++ b/drivers/usb/cdns3/gadget.c
@@ -2338,9 +2338,35 @@ static int cdns3_gadget_udc_start(struct usb_gadget *gadget,
{
struct cdns3_device *priv_dev = gadget_to_cdns3_device(gadget);
unsigned long flags;
+ enum usb_device_speed max_speed = driver->max_speed;

spin_lock_irqsave(&priv_dev->lock, flags);
priv_dev->gadget_driver = driver;
+
+ /* limit speed if necessary */
+ max_speed = min(driver->max_speed, gadget->max_speed);
+
+ switch (max_speed) {
+ case USB_SPEED_FULL:
+ writel(USB_CONF_SFORCE_FS, &priv_dev->regs->usb_conf);
+ writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf);
+ break;
+ case USB_SPEED_HIGH:
+ writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf);
+ break;
+ case USB_SPEED_SUPER:
+ break;
+ default:
+ dev_err(priv_dev->dev,
+ "invalid maximum_speed parameter %d\n",
+ max_speed);
+ /* fall through */
+ case USB_SPEED_UNKNOWN:
+ /* default to superspeed */
+ max_speed = USB_SPEED_SUPER;
+ break;
+ }
+
cdns3_gadget_config(priv_dev);
spin_unlock_irqrestore(&priv_dev->lock, flags);
return 0;
@@ -2570,12 +2596,7 @@ static int cdns3_gadget_start(struct cdns3 *cdns)
/* Check the maximum_speed parameter */
switch (max_speed) {
case USB_SPEED_FULL:
- writel(USB_CONF_SFORCE_FS, &priv_dev->regs->usb_conf);
- writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf);
- break;
case USB_SPEED_HIGH:
- writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf);
- break;
case USB_SPEED_SUPER:
break;
default:
--
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