[U-Boot] [PATCH v2 1/3] fastboot: OUT transaction length must be aligned to wMaxPacketSize

[Steve Rae]

On 15-02-13 09:59 AM, Dileep Katta wrote:
> OUT transactions must be aligned to wMaxPacketSize for each transfer,
> or else transfer will not complete successfully. This patch modifies
> rx_bytes_expected to return a transfer length that is aligned to
> wMaxPacketSize.
>
> Note that the value of wMaxPacketSize and ep->maxpacket may not be
> the same value, and it is the value of wMaxPacketSize that should be
> used for alignment.
>
> Signed-off-by: Dileep Katta <dileep.katta at linaro.org>
> ---
> Changes from v1:
> 	- Corrected source of wMaxPacketSize
>   drivers/usb/gadget/f_fastboot.c | 13 ++++++++++---
>   1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
> index a8d8205..b18452e 100644
> --- a/drivers/usb/gadget/f_fastboot.c
> +++ b/drivers/usb/gadget/f_fastboot.c
> @@ -370,13 +370,20 @@ static void cb_getvar(struct usb_ep *ep, struct usb_request *req)
>   	fastboot_tx_write_str(response);
>   }
>
> -static unsigned int rx_bytes_expected(void)
> +static unsigned int rx_bytes_expected(unsigned maxpacket)
>   {
>   	int rx_remain = download_size - download_bytes;
> +	int rem = 0;
>   	if (rx_remain < 0)
>   		return 0;
>   	if (rx_remain > EP_BUFFER_SIZE)
>   		return EP_BUFFER_SIZE;
> +	if (rx_remain < maxpacket) {
> +		rx_remain = maxpacket;
> +	} else if (rx_remain % maxpacket != 0) {
> +		rem = rx_remain % maxpacket;
> +		rx_remain = rx_remain + (maxpacket - rem);
> +	}
>   	return rx_remain;
>   }
>
> @@ -425,7 +432,7 @@ static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
>
>   		printf("\ndownloading of %d bytes finished\n", download_bytes);
>   	} else {
> -		req->length = rx_bytes_expected();
> +		req->length = rx_bytes_expected(fs_ep_out.wMaxPacketSize);
>   		if (req->length < ep->maxpacket)
>   			req->length = ep->maxpacket;
>   	}
> @@ -453,7 +460,7 @@ static void cb_download(struct usb_ep *ep, struct usb_request *req)
>   	} else {
>   		sprintf(response, "DATA%08x", download_size);
>   		req->complete = rx_handler_dl_image;
> -		req->length = rx_bytes_expected();
> +		req->length = rx_bytes_expected(fs_ep_out.wMaxPacketSize);
>   		if (req->length < ep->maxpacket)
>   			req->length = ep->maxpacket;
>   	}
>

I don't understand...
Why are we always limiting this to the "Full Speed" size?
( see fs_ep_out versus hs_ep_out defined previously in this file... )

Thanks, Steve