[U-Boot] [PATCH fix for v2014.10 2/5] usb: kbd: On a "usb reset" call usb_kbd_deregister() before calling usb_stop()

[Marek Vasut <marex@denx.de>]

On Saturday, September 20, 2014 at 04:54:35 PM, Hans de Goede wrote:
> We need to call usb_kbd_deregister() before calling usb_stop().
> 
> usbkbd's stdio_dev->priv points to the usb_device, and usb_kbd_testc
> dereferences usb_device->privptr.
> 
> usb_stop zeros usb_device, leaving usb_device->privptr NULL, causing
> bad things (tm) to happen once control returns to the main loop and
> usb_kbd_testc gets called.
> 
> Calling usb_kbd_deregister() avoids this. Note that we do not allow
> the "usb reset" to continue when the deregister fails. This will be fixed
> in a later patch.
> 
> For the same reasons always fail "usb stop" if the usb_kbd_deregister()
> fails, even in the force path. This can happen when
> CONFIG_SYS_STDIO_DEREGISTER is not set.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  common/cmd_usb.c | 27 +++++++++++++++------------
>  1 file changed, 15 insertions(+), 12 deletions(-)
> 
> diff --git a/common/cmd_usb.c b/common/cmd_usb.c
> index 2519497..b2aa44c 100644
> --- a/common/cmd_usb.c
> +++ b/common/cmd_usb.c
> @@ -430,6 +430,16 @@ static int do_usbboot(cmd_tbl_t *cmdtp, int flag, int
> argc, char * const argv[]) }
>  #endif /* CONFIG_USB_STORAGE */
> 
> +static int do_usb_stop_keyboard(void)
> +{
> +#ifdef CONFIG_USB_KEYBOARD
> +	if (usb_kbd_deregister() != 0) {
> +		printf("USB not stopped: usbkbd still using USB\n");

I tried this set of patches with the DWC2 driver on RPI just now and i get this 
message and 'usb start' fails and doesn't scan bus. I suspect we have a problem 
here, can you check and post a fix ?

Best regards,
Marek Vasut