[U-Boot] [PATCH v1] Revert "fastboot: OUT transaction length must be aligned to wMaxPacketSize"

[Lukasz Majewski]

Hi Marek,

> On 03/23/2016 01:50 AM, Steve Rae wrote:
> > This reverts commit 9e4b510d40310bf46e09f4edd0a0b6356213df47.
> > 
> > Signed-off-by: Steve Rae <srae at broadcom.com>
> > ---
> > As discussed on the mailing list, this change breaks the download
> > portion of fastboot by causing the server (the device running
> > U-Boot) to wait forever for bytes which are never sent by the
> > client (the host connected via USB).
> 
> It'd be real cool if you could reference the ML discussion next time.
> 
> > Does anyone know how to contact:
> >   Dileep Katta <dileep.katta at linaro.org>
> > (this email bounces) ?
> 
> No clue, sorry.

Probably he is no longer employed by Linaro.

> 
> Applied for now as it fixes real bug.

I've a gut feeling that there are different versions of "fastboot"
protocol.

What Steve is describing is that HOST is waiting for ZLP ACK.

Anyway, I'm not able to test fastboot gadget since our (I mean
Samsung's) boards aren't supporting fastboot - we use UMS, DFU, LTHOR.

Hence, I can only rely on somebody's testing and review the code without
the ability to know about implementation "quirks".

> 
> >  drivers/usb/gadget/f_fastboot.c | 27 +++++----------------------
> >  1 file changed, 5 insertions(+), 22 deletions(-)
> > 
> > diff --git a/drivers/usb/gadget/f_fastboot.c
> > b/drivers/usb/gadget/f_fastboot.c index a54b4ee..887cf4f 100644
> > --- a/drivers/usb/gadget/f_fastboot.c
> > +++ b/drivers/usb/gadget/f_fastboot.c
> > @@ -57,7 +57,6 @@ 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,
> > @@ -241,13 +240,10 @@ 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);
> > -		is_high_speed = true;
> > -	} else {
> > +	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;
> > @@ -419,20 +415,13 @@ 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(void)
> >  {
> >  	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;
> >  }
> >  
> > @@ -444,7 +433,6 @@ 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);
> > @@ -482,9 +470,7 @@ 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);
> > +		req->length = rx_bytes_expected();
> >  		if (req->length < ep->maxpacket)
> >  			req->length = ep->maxpacket;
> >  	}
> > @@ -497,7 +483,6 @@ 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);
> > @@ -513,9 +498,7 @@ 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);
> > +		req->length = rx_bytes_expected();
> >  		if (req->length < ep->maxpacket)
> >  			req->length = ep->maxpacket;
> >  	}
> > 
> 
> 



-- 
Best regards,

Lukasz Majewski

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