Re: [PATCH v3 0/6] usb: host: change TPL support behaviour

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On Thu, Sep 11, 2014 at 07:57:12AM +0800, Peter Chen wrote:
> On Fri, Sep 05, 2014 at 10:08:02AM -0400, Alan Stern wrote:
> > On Fri, 5 Sep 2014, Peter Chen wrote:
> > 
> > > On Thu, Sep 04, 2014 at 11:12:42AM -0400, Alan Stern wrote:
> > > > On Thu, 4 Sep 2014, Peter Chen wrote:
> > > > 
> > > > > On Wed, Sep 03, 2014 at 09:48:15PM -0400, Alan Stern wrote:
> > > > > > On Thu, 4 Sep 2014, Peter Chen wrote:
> > > > > > 
> > > > > > > > > > Hi Greg & Alan, any comments for this patchset?
> > > > > > > > > 
> > > > > > > > > In patch 2/6, why did you move the !is_targeted(udev) code from 
> > > > > > > > > usb_enumerate_device_otg() to usb_enumerate_device()?  Why not leave 
> > > > > > > > > the code where it is?
> > > > > > > > > 
> > > > > > > > 
> > > > > > > > TPL support is also needed for embedded host, not only otg host.
> > > > > > 
> > > > > > But usb_enumerate_device_otg() gets called for all types of 
> > > > > > host, right?  At least, it gets called whenever usb_enumerate_device() 
> > > > > > runs.
> > > > > > 
> > > > > > Yes, it contains "#ifdef CONFIG_USB_OTG".  But your patch has "if (... 
> > > > > > && IS_ENABLED(CONFIG_USB_OTG))", so the behavior is the same.  Why 
> > > > > > move the code if there's no change in behavior?
> > > > > > 
> > > > > 
> > > > > At former code, the tpl support judgement (in function is_targeted) will
> > > > > only be called if CONFIG_USB_OTG is defined, but now, we need tpl support
> > > > > for all targeted hosts.
> > > > > 
> > > > > Why we need IS_ENABLED(CONFIG_USB_OTG) as last conditions at if conditions,
> > > > > the reason is the operation which the B-device may want switch to host even
> > > > > if it is not at A's TPL is only for OTG host.
> > > > 
> > > > The only side effect in is_targeted() is the dev_err() message.  Are 
> > > > you saying that this dev_err() message needs to appear even when 
> > > > CONFIG_USB_OTG is disabled?
> > > > 
> > > 
> > > Yes, both embedded host and otg host CAN support TPL, if the embedded host
> > > SHOULD support TPL, it should show an err message if the unsupported device is
> > > on the port.
> > > 
> > > At OTG & EH compliance test plan,
> > > (http://www.usb.org/developers/onthego/otgeh_compliance_plan_1_2.pdf)
> > > page 124, the chapter 7.3.6 A-UUT Unsupported device Message test, it needs host
> > > prints "Unsupported Device" if the attaching device is not supported
> > > (without at Targeted Peripheral List).
> > 
> > Okay, then I have no objections to this patch series.
> > 
> > Alan Stern
> 
> Hi Greg,
> 
> Will you queue this patchset?

Ok, will do, give me a day or so, thanks,

greg k-h
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