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

[Felipe Balbi <felipe.balbi@linux.intel.com>]

Hi,

Roger Quadros <rogerq@ti.com> writes:

> 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.

if you want this in -rc, you should have a Fixes line there.

> 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;

seems like this can be simplified a little:

	switch (max_speed) {
        case USB_SPEED_FULL:
        	writel(USB_CONF_SFORCE_FS, &priv_dev->regs->usb_conf);
                /* fallthrough */
        case USB_SPEED_HIGH:
		writel(USB_CONF_USB3DIS, &priv_dev->regs->usb_conf);
                /* fallthrough */
	case USB_SPEED_SUPER:
		break;

	[...]

		
-- 
balbi