From: Zhuang Jin Can <jin.can.zhuang@intel.com>
To: Felipe Balbi <balbi@ti.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
linux-usb@vger.kernel.org, linux-omap@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: dwc3: gadget: fix burst size corruption
Date: Fri, 2 May 2014 23:35:44 -0400 [thread overview]
Message-ID: <20140503033544.GA19925@intel.com> (raw)
In-Reply-To: <20140501151500.GC6355@saruman.home>
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
prev parent reply other threads:[~2014-05-03 3:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-01 7:16 [PATCH] usb: dwc3: gadget: fix burst size corruption Zhuang Jin Can
2014-04-30 20:03 ` Felipe Balbi
2014-05-01 21:14 ` Zhuang Jin Can
2014-05-01 13:45 ` Alan Stern
2014-05-01 15:15 ` Felipe Balbi
2014-05-03 3:35 ` Zhuang Jin Can [this message]
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