lkml.org 
[lkml]   [2014]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRE: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0



> -----Original Message-----
> From: Peter Chen [mailto:peter.chen@freescale.com]
> Sent: 2014年2月25日 9:19
> To: Neil Zhang
> Cc: balbi@ti.com; gregkh@linuxfoundation.org; linux-usb@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0
>
> On Mon, Feb 24, 2014 at 04:03:12PM +0800, Neil Zhang wrote:
> > Hardware zlt will try to send the zero length packet automatically
> > when the data transferd is multiple times of max packet, this will
> > cause issues on Windows.
> > So let's disable HW zlt by default.
>
> Would you have description that what kinds of issue on Windows if zlt is is
> selected?
>

Enumeration will fail.

> Peter
>
> >
> > Signed-off-by: Neil Zhang <zhangwm@marvell.com>
> > ---
> > drivers/usb/gadget/mv_udc_core.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/gadget/mv_udc_core.c
> > b/drivers/usb/gadget/mv_udc_core.c
> > index ebc0dfd..657ac5c 100644
> > --- a/drivers/usb/gadget/mv_udc_core.c
> > +++ b/drivers/usb/gadget/mv_udc_core.c
> > @@ -89,7 +89,7 @@ static void ep0_reset(struct mv_udc *udc)
> > /* configure ep0 endpoint capabilities in dQH */
> > ep->dqh->max_packet_length =
> > (EP0_MAX_PKT_SIZE << EP_QUEUE_HEAD_MAX_PKT_LEN_POS)
> > - | EP_QUEUE_HEAD_IOS;
> > + | EP_QUEUE_HEAD_IOS | EP_QUEUE_HEAD_ZLT_SEL;
> >
> > ep->dqh->next_dtd_ptr = EP_QUEUE_HEAD_NEXT_TERMINATE;
> >
> > --
> > 1.7.9.5
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-usb"
> > in the body of a message to majordomo@vger.kernel.org More majordomo
> > info at http://vger.kernel.org/majordomo-info.html
> >
> >
>
> --
>
> Best Regards,
> Peter Chen


Best Regards,
Neil Zhang
\
 
 \ /
  Last update: 2014-02-25 06:01    [W:0.163 / U:0.628 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site