Re: [PATCH] usb: dwc3: gadget: fix burst size corruption

[Alan Stern]

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.

Alan Stern

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