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Date:   Fri, 17 Dec 2021 16:19:20 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Mathias Nyman <mathias.nyman@linux.intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Lu Baolu <baolu.lu@linux.intel.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        Chunfeng Yun <chunfeng.yun@mediatek.com>
Subject: Re: earlyprintk=xdbc seems broken
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On Fri, Dec 17, 2021 at 02:55:07PM +0100, Peter Zijlstra wrote:
> On Fri, Dec 17, 2021 at 01:01:43PM +0200, Mathias Nyman wrote:
> > I can reproduce this.
> > Looks like problems started when driver converted to readl_poll_timeout_atomic() in:
> > 
> > 796eed4b2342 usb: early: convert to readl_poll_timeout_atomic()
> 
> I can confirm, reverting that solves the boot hang, things aren't quite
> working for me though.
> 
> > Seems to hang when read_poll_timeout_atomic() calls ktime_* functions.
> > Maybe  it's too early for ktime.
> 
> It certainly is, using ktime for delay loops sounds daft to me anyhow.

It was a "find a pattern and replace it with a function call" type of
cleanup series.  It's obviously wrong, I will go revert it now.

thanks,

greg k-h