[U-Boot] [PATCH] usb: Add delay to fix USB 2.0 stick enumeration failure on LS208xA

Marek Vasut marex at denx.de
Mon Nov 13 09:33:39 UTC 2017


On 11/13/2017 10:00 AM, Ran Wang wrote:
> Force delay 10ms between each control messages to fix Transcend
> and Kingston DT 101 G2 USB2.0 stick fail to be enumerated by LS208xA.

That means everyone else also suffers this burden, even though it's a
problem specific to LS208x ? What is the real problem here ?

> Signed-off-by: Ran Wang <ran.wang_1 at nxp.com>
> ---
>  common/usb.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/common/usb.c b/common/usb.c
> index 0904259757..eeacc80b9e 100644
> --- a/common/usb.c
> +++ b/common/usb.c
> @@ -223,6 +223,9 @@ int usb_control_msg(struct usb_device *dev, unsigned int pipe,
>  		return -EINVAL;
>  	}
>  
> +	/* Add delay to support more devices' enumeration */
> +	mdelay(10);
> +
>  	/* set setup command */
>  	setup_packet->requesttype = requesttype;
>  	setup_packet->request = request;
> 


-- 
Best regards,
Marek Vasut


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