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Date: Tue, 11 Feb 2014 12:41:41 +0000
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Message-ID: <20140211124140.GC2509@work-vm>
References: <153a8e98437c7d4b7fc3df2bf375fbc9e0bdb8ef.1392101145.git.peter.crosthwaite@xilinx.com>
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Subject: Re: [Qemu-devel] [PATCH bugfix v1 1/1] char/serial: Fix
 emptynesscheckk
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To: Alex Benn?e <alex.bennee@linaro.org>
Cc: peter.maydell@linaro.org, Peter Crosthwaite <peter.crosthwaite@xilinx.com>, mjt@tls.msk.ru, qemu-devel@nongnu.org, edgari@xilinx.com, mkletzan@redhat.com

* Alex Benn?e (alex.bennee@linaro.org) wrote:
> 
> Dr. David Alan Gilbert <dgilbert@redhat.com> writes:
> 
> > * Peter Crosthwaite (peter.crosthwaite@xilinx.com) wrote:
> >> This was guarding against a full fifo rather than an empty fifo when
> >> popping. Fix.
> >> 
> >> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> >> ---
> >
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >
> > I think this brings it back to how it was on the old FIFO code.
> 
> This does make me wonder why it was changed? Was there another crashing
> case it fixed?

The old serial code had it's own FIFO implementation, and that was
removed so that we had one less FIFO in the codebase; the problem
was that the old one in the serial code just returned 0 when empty,
the shared one aborts.

Dave
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK