Messages in this thread |  | | From | Neil Zhang <> | Date | Mon, 24 Feb 2014 23:11:39 -0800 | Subject | RE: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0 |
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> -----Original Message----- > From: Peter Chen [mailto:Peter.Chen@freescale.com] > Sent: 2014年2月25日 13:15 > 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. > > > > What causes enumeration fail, why it does not occur before? > A unexpected zero packet cause enumeration fail. It's not easy that the descriptor is actually 1024 bytes, so not easy to be found.
> Peter
Best Regards, Neil Zhang
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