[U-Boot] [PATCH 1/3] fastboot: Clean up bulk-out logic

[Lukasz Majewski]

Hi Roger,

> Just use ep->maxpacket to get the maxpacket size
> and simplify the bulk-out maxpacket alignment.
> 
> Signed-off-by: Roger Quadros <rogerq at ti.com>
> Tested-by: Steve Rae <srae at broadcom.com>
> ---
>  drivers/usb/gadget/f_fastboot.c | 50
> +++++++++++++++++++---------------------- 1 file changed, 23
> insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/usb/gadget/f_fastboot.c
> b/drivers/usb/gadget/f_fastboot.c index 7961231..28b244a 100644
> --- a/drivers/usb/gadget/f_fastboot.c
> +++ b/drivers/usb/gadget/f_fastboot.c
> @@ -39,6 +39,11 @@
>  #define TX_ENDPOINT_MAXIMUM_PACKET_SIZE      (0x0040)
>  
>  #define EP_BUFFER_SIZE			4096
> +/*
> + * EP_BUFFER_SIZE must always be an integral multiple of maxpacket
> size
> + * (64 or 512 or 1024), else we break on certain controllers like
> DWC3
> + * that expect bulk OUT requests to be divisible by maxpacket size.
> + */
>  
>  struct f_fastboot {
>  	struct usb_function usb_function;
> @@ -57,7 +62,6 @@ static struct f_fastboot *fastboot_func;
>  static unsigned int fastboot_flash_session_id;
>  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,
> @@ -269,11 +273,6 @@ static int fastboot_set_alt(struct usb_function
> *f, debug("%s: func: %s intf: %d alt: %d\n",
>  	      __func__, f->name, interface, alt);
>  
> -	if (gadget->speed == USB_SPEED_HIGH)
> -		is_high_speed = true;
> -	else
> -		is_high_speed = false;
> -
>  	d = fb_ep_desc(gadget, &fs_ep_out, &hs_ep_out);
>  	ret = usb_ep_enable(f_fb->out_ep, d);
>  	if (ret) {
> @@ -455,20 +454,27 @@ static void cb_getvar(struct usb_ep *ep, struct
> usb_request *req) fastboot_tx_write_str(response);
>  }
>  
> -static unsigned int rx_bytes_expected(unsigned int maxpacket)
> +static unsigned int rx_bytes_expected(struct usb_ep *ep)
>  {
>  	int rx_remain = download_size - download_bytes;
> -	int rem = 0;
> -	if (rx_remain < 0)
> +	unsigned int rem;
> +	unsigned int maxpacket = ep->maxpacket;
> +
> +	if (rx_remain <= 0)
>  		return 0;
> -	if (rx_remain > EP_BUFFER_SIZE)
> +	else 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;
> +
> +	/*
> +	 * Some controllers e.g. DWC3 don't like OUT transfers to be
> +	 * not ending in maxpacket boundary. So just make them happy
> by
> +	 * always requesting for integral multiple of maxpackets.
> +	 * This shouldn't bother controllers that don't care about
> it.
> +	 */
> +	rem = rx_remain % maxpacket;
> +	if (rem > 0)
>  		rx_remain = rx_remain + (maxpacket - rem);
> -	}
> +
>  	return rx_remain;
>  }
>  
> @@ -480,7 +486,6 @@ 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);
> @@ -518,11 +523,7 @@ static void rx_handler_dl_image(struct usb_ep
> *ep, struct usb_request *req) 
>  		printf("\ndownloading of %d bytes finished\n",
> download_bytes); } else {
> -		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;
> +		req->length = rx_bytes_expected(ep);
>  	}
>  
>  	req->actual = 0;
> @@ -533,7 +534,6 @@ static void cb_download(struct usb_ep *ep, struct
> usb_request *req) {
>  	char *cmd = req->buf;
>  	char response[FASTBOOT_RESPONSE_LEN];
> -	unsigned int max;
>  
>  	strsep(&cmd, ":");
>  	download_size = simple_strtoul(cmd, NULL, 16);
> @@ -549,11 +549,7 @@ 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;
> -		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;
> +		req->length = rx_bytes_expected(ep);
>  	}
>  	fastboot_tx_write_str(response);
>  }

Reviewed-by: Lukasz Majewski <l.majewski at samsung.com>

-- 
Best regards,

Lukasz Majewski

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