4.14-stable review patch. If anyone has any objections, please let me know.
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From: Roger Quadros rogerq@ti.com
commit a4f0927ef588cf62bb864707261482c874352942 upstream.
Currently UDC core calls ->udc_set_speed() with the speed parameter containing the maximum speed supported by the gadget function driver. This might very well be more than that supported by the UDC controller driver.
Select the lesser of the 2 speeds so both UDC and gadget function driver are operating within limits.
This fixes PHY Erratic errors and 2 second enumeration delay on TI's AM437x platforms.
Fixes: 6099eca796ae ("usb: gadget: core: introduce ->udc_set_speed() method") Reported-by: Dylan Howey Dylan.Howey@tennantco.com Signed-off-by: Roger Quadros rogerq@ti.com Signed-off-by: Felipe Balbi felipe.balbi@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/gadget/udc/core.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
--- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1080,8 +1080,12 @@ static inline void usb_gadget_udc_stop(s static inline void usb_gadget_udc_set_speed(struct usb_udc *udc, enum usb_device_speed speed) { - if (udc->gadget->ops->udc_set_speed) - udc->gadget->ops->udc_set_speed(udc->gadget, speed); + if (udc->gadget->ops->udc_set_speed) { + enum usb_device_speed s; + + s = min(speed, udc->gadget->max_speed); + udc->gadget->ops->udc_set_speed(udc->gadget, s); + } }
/**