[U-Boot] [PATCH 2/3] usb: s3c-otg: Fix short packet for request size > ep.maxpacket

Lukasz Majewski l.majewski at samsung.com
Tue Apr 19 13:25:02 CEST 2016


Hi Roger,

> Hi Lukasz,
> 
> On 19/04/16 12:02, Lukasz Majewski wrote:
> > Hi Roger,
> > 
> >> Request size can be greater than ep.packet and still end in a
> >> short packet. We need to tackle this case as end of transfer
> >> (if short_not_ok is not set) as indicated in USB 2.0 Specification
> >> [1], else we get stuck up on certain protocols like fastboot.
> >>
> >> [1] - USB2.0 Specification, Section 5.3.2 Pipes
> >>
> >> Reported-by: Steve Rae <steve.rae at broadcom.com>
> >> Signed-off-by: Roger Quadros <rogerq at ti.com>
> >> Tested-by: Steve Rae <steve.rae at broadcom.com>
> >> ---
> >>  drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c
> >> b/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c index bce9c30..a31d875
> >> 100644 --- a/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c
> >> +++ b/drivers/usb/gadget/dwc2_udc_otg_xfer_dma.c
> >> @@ -229,7 +229,7 @@ static void complete_rx(struct dwc2_udc *dev,
> >> u8 ep_num) ROUND(xfer_size, CONFIG_SYS_CACHELINE_SIZE));
> >>  
> >>  	req->req.actual += min(xfer_size, req->req.length -
> >> req->req.actual);
> >> -	is_short = (xfer_size < ep->ep.maxpacket);
> >> +	is_short = xfer_size % ep->ep.maxpacket;
> > 
> > is_short is a flag - so maybe it would be better to write something
> > like:
> 
> but it is defined as u32 so I thought it might as well print the
> short packet length instead of just 1/0.

I mean that it looks strange for me in debug message when one see:

"is_short: 8" (as it was shown at Steve's output).


> 
> > 
> > is_short = !!(xfer_size % ep->ep.maxpacket)) ?
> > 
> > I'm going to test those patches on my boards. I will share the
> > results ASAP.
> > 
> >>  
> >>  	debug_cond(DEBUG_OUT_EP != 0,
> >>  		   "%s: RX DMA done : ep = %d, rx bytes = %d/%d, "
> > 
> > 
> > 
> 
> --
> cheers,
> -roger
> 



-- 
Best regards,

Lukasz Majewski

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


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