usb: gadget: core: Fix ->udc_set_speed() speed handling

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")
Cc: <stable@vger.kernel.org> # v4.13+
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>
This commit is contained in:
Roger Quadros 2017-10-31 15:56:29 +02:00 • committed by Felipe Balbi
commit a4f0927ef5