[U-Boot] [PATCH 07/14] usb: Read device descriptor after device is addressed for xHCI

[Stefan Roese]

On 18.09.2017 15:40, Bin Meng wrote:
> For xHCI it is not possible to read a device descriptor before it
> has been assigned an address. That's why usb_setup_descriptor()
> was called with 'do_read' being false. But we really need try to
> read the device descriptor before starting any real communication
> with the default control endpoint.
> 
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
> 
>   common/usb.c | 11 +++++++++++
>   1 file changed, 11 insertions(+)
> 
> diff --git a/common/usb.c b/common/usb.c
> index 88cee81..8d27bc7 100644
> --- a/common/usb.c
> +++ b/common/usb.c
> @@ -1052,6 +1052,17 @@ static int usb_prepare_device(struct usb_device *dev, int addr, bool do_read,
>   
>   	mdelay(10);	/* Let the SET_ADDRESS settle */
>   
> +	/*
> +	 * If we haven't read device descriptor before, read it here
> +	 * after device is assigned an address. This is only applicable
> +	 * to xHCI so far.
> +	 */
> +	if (!do_read) {
> +		err = usb_setup_descriptor(dev, true);
> +		if (err)
> +			return err;
> +	}
> +
>   	return 0;
>   }
>   
> 

Reviewed-by: Stefan Roese <sr at denx.de>
Tested-by: Stefan Roese <sr at denx.de>

Thanks,
Stefan