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Subject: Re: [RESEND PATCH v2 1/4] usb: dbc: early driver for xhci debug
 capability
To: Peter Zijlstra <peterz@infradead.org>
References: <1476836305-4468-1-git-send-email-baolu.lu@linux.intel.com>
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Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        Ingo Molnar <mingo@redhat.com>, linux-usb@vger.kernel.org,
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From: Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <580962E0.4000209@linux.intel.com>
Date: Fri, 21 Oct 2016 08:35:44 +0800
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Hi Peter,

On 10/20/2016 05:08 PM, Peter Zijlstra wrote:
> On Thu, Oct 20, 2016 at 10:41:32AM +0200, Peter Zijlstra wrote:
>> I'm already only using early_printk() because regular printk() is an
>> unfixable piece of crap, and now you're making early_printk() useless
>> too.
> Note that the existing USB debug port stuff doesn't seem to have a
> single lock in. Its just polling on readl and doing writel without any
> serialization what so ever.
>
> Not that I've ever actually used it (lack of the magic cable), but it at
> least looks like it should mostly work.
>

Thank you again.

Your comments make sense to me. I will remove the lock and work
queue usages in the new version.

Best regards,
Lu Baolu