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From: Paul Mundt <lethal@linux-sh.org>
To: linux-sh@vger.kernel.org
Subject: Re: Serial port RTPM/Suspend issues
Date: Tue, 12 Mar 2013 15:41:41 +0000	[thread overview]
Message-ID: <20130312154140.GB20355@linux-sh.org> (raw)
In-Reply-To: <CABYn4szDUQpgsSErNV6e+f8z9-FdpzzZkhafC5qELdK=kWk6=w@mail.gmail.com>

On Tue, Mar 12, 2013 at 04:31:57PM +0100, Bastian Hecht wrote:
> 2013/3/12 Paul Mundt <lethal@linux-sh.org>:
> > On Tue, Mar 12, 2013 at 03:50:42PM +0100, Bastian Hecht wrote:
> >> To avoid confusion, let me add: Garbage is produced when waking, not
> >> in the shutdown process.
> >
> > I assume this is just data left in the FIFO that hasn't been drained that
> > comes back in an undefined state due to losing the clock?
> 
> The port hangs after printing a couple of dozens of characters. The
> system itself seems stable - I can log into it using ssh.
> Does this fit with your theory?
> 
There are two theories really, residual FIFO data or baud rate generation
issues. Your dozens of characters thing seems to support the former,
given the FIFO size -- the latter would more likely generate a lot more
spew.

> By the way I am using a shallow sleep to test it. Just cpu_do_idle().

Can you see how it goes booting with nohlt? We have seen issues between
BL bit and sleep interactivity before.

  parent reply	other threads:[~2013-03-12 15:41 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-12 14:41 Serial port RTPM/Suspend issues Bastian Hecht
2013-03-12 14:50 ` Bastian Hecht
2013-03-12 14:54 ` Paul Mundt
2013-03-12 15:31 ` Bastian Hecht
2013-03-12 15:41 ` Paul Mundt [this message]
2013-03-13 10:11 ` Bastian Hecht
2013-03-13 10:31 ` Bastian Hecht

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