From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhuang Jin Can Subject: Re: [PATCH] usb: dwc3: gadget: fix burst size corruption Date: Fri, 2 May 2014 23:35:44 -0400 Message-ID: <20140503033544.GA19925@intel.com> References: <20140501211424.GE30575@intel.com> <20140501151500.GC6355@saruman.home> Reply-To: jin.can.zhuang@intel.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140501151500.GC6355@saruman.home> Sender: linux-kernel-owner@vger.kernel.org To: Felipe Balbi Cc: Alan Stern , linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-omap@vger.kernel.org Hi, On Thu, May 01, 2014 at 10:15:00AM -0500, Felipe Balbi wrote: > On Thu, May 01, 2014 at 09:45:17AM -0400, Alan Stern wrote: > > On Thu, 1 May 2014, Zhuang Jin Can wrote: > > > > again, you found a bug on the gadget driver. Fix that. composite.c > > > > guarantees that for those functions which don't pass bMaxBurst, > > > > gadget->maxburst will be set to *at least* 1. > > > > > > > I agree the real fix should be in the gadget driver. The patch intents > > > to prevent hibernatition from being corrupted by a bad gadget driver. > > > If OEMs develop their own gadget driver forgetting to call > > > config_ep_by_speed(), it'll turn out to be everything works except > > > dwc3 hibernation, and they'll complain to dwc3. f_ffs is an > > > example has SuperSpeed support but doesn't call config_ep_by_speed(). > > > It's just for robustness, and dwc3 is not doing anything wrong. > > > It did cause me a long time to figure out why the hibernation was broken. > > > > You could include the check, for the sake of robustness, in dwc3 -- but > > if it fails, you should write a message to the kernel log saying that > > the gadget driver needs to be fixed. I admit the fix is too paranoid. Thanks your comment. > > Also, if we're adding something to dwc3, we need to add to other > USB3-capable UDCs too. Namely dummy and marvel's. So I think the fix is not valuable to you. Thanks for your comment. And I'm new to communitiy, hope you can bear with me:) Jincan