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Re: [Xen-devel] [PATCH] xen: more robust serial port driver

To: Christoph Egger <Christoph.Egger@xxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] xen: more robust serial port driver
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 28 Jul 2009 15:58:41 +0100
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On 28/07/2009 15:47, "Christoph Egger" <Christoph.Egger@xxxxxxx> wrote:

>> Might this be the case for the udelay(100) as
>> well?
> No. This ensures, that the write takes effect before the read happens.

Can a read really overtake a write in this case? Seriously?

>> And what kinds of systems have these broken UARTs that half-advertise
>> a broken/non-existent FIFO?
> The original ns16550 has a broken FIFO. The ns16450 has no FIFO.
> There are simulators which simulate those old things instead of a ns16550a.

Hm, well, okay, the actual one line core of this patch actually seems okay
to me. It's all the rest I want to drop on the floor.

 -- Keir

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