Patch "usb: gadget: core: Fix ->udc_set_speed() speed handling" has been added to the 4.14-stable tree

Patch "usb: gadget: core: Fix ->udc_set_speed() speed handling" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-gadget-core-fix-udc_set_speed-speed-handling.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a4f0927ef588cf62bb864707261482c874352942 Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq@ti.com>
Date: Tue, 31 Oct 2017 15:56:29 +0200
Subject: usb: gadget: core: Fix ->udc_set_speed() speed handling

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);
+	}
 }
 
 /**


Patches currently in stable-queue which might be from rogerq@ti.com are

queue-4.14/usb-gadget-core-fix-udc_set_speed-speed-handling.patch