Date: Fri, 22 May 2015 09:12:44 -0700
From: David Cohen <david.a.cohen@linux.intel.com>
To: "Lu, Baolu" <baolu.lu@linux.intel.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        qiuxu.zhuo@intel.com
Subject: Re: [PATCH v2 1/1] usb: ulpi: ulpi_init should be executed in
 subsys_initcall
Message-ID: <20150522161244.GB31627@psi-dev26.jf.intel.com>
References: <1432260425-2350-1-git-send-email-baolu.lu@linux.intel.com>
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 <20150522031127.GB28433@psi-dev26.jf.intel.com>
 <555ED0CF.3060903@linux.intel.com>
 <555EDFD7.6000605@linux.intel.com>
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On Fri, May 22, 2015 at 03:50:47PM +0800, Lu, Baolu wrote:
> 
> 
> On 05/22/2015 02:46 PM, Lu, Baolu wrote:
> >
> >
> >On 05/22/2015 11:11 AM, David Cohen wrote:
> >>On Thu, May 21, 2015 at 08:09:54PM -0700, David Cohen wrote:
> >>>Hi,
> >>>
> >>>On Fri, May 22, 2015 at 10:07:05AM +0800, Lu Baolu wrote:
> >>>>Many drivers and modules depend on ULPI bus registeration to
> >>>>register ULPI interfaces and drivers. It's more appropriate
> >>>>to register ULPI bus in subsys_initcall instead of module_init.
> >>>>
> >>>>Kernel panic has been reported with some kind of kernel config.
> >>>Even though I agree subsys_initcall is better to register ulpi bus,
> >>>it's
> >>>still no excuse to have kernel panic. What about ULPI bus being
> >>>compiled
> >>>as module?
> >
> >No kernel panic if ULPI is built as a module.
> >
> >>>IMHO this is avoiding the proper kernel panic fix which should be
> >>>failing gracefully (or defer probe) from tusb1210 driver.
> >>Maybe I need to express myself better :)
> >>IMHO we should not consider work done with this patch only. It's still
> >>incomplete.
> >
> >I am with you on that we should know the real problem.
> >
> >I could go ahead with further debugging. Do you have any suggestions
> >about which direction should I go?
> 
> I forgot to mention that the panic was found in an Android environment.
> The kernel version is  v4.1-rc3.

FWIW:

The problem with Android environment is the amount of off-tree patches
you may have over there.
For upstream tasks, I'd suggest use a clean tree + patches you want to
test. Usually yocto looks more friendly to test under this environment.

Br, David

> 
> >
> >>
> >>Br, David
> >
> >Thank you,
> >-Baolu
> >
> >>-- 
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> >>
> >
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