> -----Original Message----- > From: Felipe Balbi [mailto:balbi@xxxxxx] > Sent: 2014年2月26日 23:19 > To: Neil Zhang > Cc: balbi@xxxxxx; Peter Chen; gregkh@xxxxxxxxxxxxxxxxxxx; > linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Alexander Shishkin > Subject: Re: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0 > > Hi, > > On Tue, Feb 25, 2014 at 05:48:17PM -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. > > > > > > > > > > > > > Chipidea bug too? Does it follow ch 8.5.3.2 Variable-length Data > > > > Stage, USB > > > 2.0 spec? > > > > > > wait, this is a chipidea core ? Why aren't you guys using the > > > chipidea driver yet ? You need to switch over to that driver dude, > > > we can't have duplicated code in the tree. > > > > > > I'm sorry, but I won't be taking this series, please use chipidea > > > driver, it should be very simple to add a glue layer for your core to the > chipidea driver. > > > > > > > Yes, it use chipidea IP. > > But the driver is earlier than the chipidea one and we use it for our > > products. > > So it may be not that easy to switch to chipidea driver due to the > > stability. > > that's nonsense, the average chipidea glue layer is ~80 LOCs. You can write > that in less than 2 hours and give it a try. We cannot have duplicate drivers in > the tree and development effort *must* be shared. > > If you guys use the same IP, why wouldn't you use the same chipidea driver ? > > sorry, you didn't convince me. It's too sad! Anyway we will estimate the chipidea driver to see whether it meets our requirement. > > -- > Balbi Best Regards, Neil Zhang ?韬{.n?????%??檩??w?{.n???{炳???骅w* jg????????G??⒏ ⒎?:+v???????? ????＂??????
