[U-Boot] [PATCH v3 1/3] fastboot: OUT transaction length must be aligned to wMaxPacketSize

[Lukasz Majewski]

Hi Dileep,

> 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. wMaxPacketSize is passed depending on the speed of
> connection.
> 
> Signed-off-by: Dileep Katta <dileep.katta at linaro.org>
> ---
> Changes in v2:
> 	- Corrected source of wMaxPacketSize
> Changes in v3:
> 	- Corrected the logic to accomodate both HS and FS speeds
> 
>  drivers/usb/gadget/f_fastboot.c | 27 ++++++++++++++++++++++-----
>  1 file changed, 22 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/gadget/f_fastboot.c
> b/drivers/usb/gadget/f_fastboot.c index a8d8205..2793590 100644
> --- a/drivers/usb/gadget/f_fastboot.c
> +++ b/drivers/usb/gadget/f_fastboot.c
> @@ -55,6 +55,7 @@ static inline struct f_fastboot
> *func_to_fastboot(struct usb_function *f) static struct f_fastboot
> *fastboot_func; static unsigned int download_size;
>  static unsigned int download_bytes;
> +static bool is_high_speed;
>  
>  static struct usb_endpoint_descriptor fs_ep_in = {
>  	.bLength            = USB_DT_ENDPOINT_SIZE,
> @@ -219,10 +220,13 @@ static int fastboot_set_alt(struct usb_function
> *f, __func__, f->name, interface, alt);
>  
>  	/* make sure we don't enable the ep twice */
> -	if (gadget->speed == USB_SPEED_HIGH)
> +	if (gadget->speed == USB_SPEED_HIGH) {
>  		ret = usb_ep_enable(f_fb->out_ep, &hs_ep_out);
> -	else
> +		is_high_speed = true;
> +	} else {
>  		ret = usb_ep_enable(f_fb->out_ep, &fs_ep_out);
> +		is_high_speed = false;
> +	}
>  	if (ret) {
>  		puts("failed to enable out ep\n");
>  		return ret;
> @@ -370,13 +374,20 @@ 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 int 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;
>  }
>  
> @@ -388,6 +399,7 @@ static void rx_handler_dl_image(struct usb_ep
> *ep, struct usb_request *req) const unsigned char *buffer = req->buf;
>  	unsigned int buffer_size = req->actual;
>  	unsigned int pre_dot_num, now_dot_num;
> +	unsigned int max;
>  
>  	if (req->status != 0) {
>  		printf("Bad status: %d\n", req->status);
> @@ -425,7 +437,9 @@ 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();
> +		max = is_high_speed ? hs_ep_out.wMaxPacketSize :
> +				fs_ep_out.wMaxPacketSize;
> +		req->length = rx_bytes_expected(max);
>  		if (req->length < ep->maxpacket)
>  			req->length = ep->maxpacket;
>  	}
> @@ -438,6 +452,7 @@ static void cb_download(struct usb_ep *ep, struct
> usb_request *req) {
>  	char *cmd = req->buf;
>  	char response[RESPONSE_LEN];
> +	unsigned int max;
>  
>  	strsep(&cmd, ":");
>  	download_size = simple_strtoul(cmd, NULL, 16);
> @@ -453,7 +468,9 @@ 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();
> +		max = is_high_speed ? hs_ep_out.wMaxPacketSize :
> +			fs_ep_out.wMaxPacketSize;
> +		req->length = rx_bytes_expected(max);
>  		if (req->length < ep->maxpacket)
>  			req->length = ep->maxpacket;
>  	}

Applied to u-boot-dfu branch.

Thanks for the patch!

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group