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From: "H. Peter Anvin" <hpa@zytor.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Simon Kagstrom <simon.kagstrom@netinsight.net>,
	x86@kernel.org, linux-serial@vger.kernel.org,
	linux-kernel@vger.kernel.org, mingo@redhat.com,
	tglx@linutronix.de, alan@linux.intel.com,
	akpm@linux-foundation.org
Subject: Re: [PATCH 1/2]: serial8250: Use native_io_delay on the x86
Date: Wed, 17 Mar 2010 11:43:54 -0700	[thread overview]
Message-ID: <4BA122EA.9030305@zytor.com> (raw)
In-Reply-To: <20100317183608.600bcdf0@lxorguk.ukuu.org.uk>

On 03/17/2010 11:36 AM, Alan Cox wrote:
>
> You just need a write to something on the ISA bus which is 'safe' so that
> you don't end up reading back what you wrote to an non-existant port as
> some old chipsets will return the last ISA result when you do this rather
> than 0xff.

Ah... floating bus syndrome.  So how about writing 0xff to the SCR 
register in the same register range?

	-hpa

  reply	other threads:[~2010-03-17 18:44 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-17 12:28 [PATCH 0/2]: x86: Honor IO_DELAY IO port settings Simon Kagstrom
2010-03-17 12:30 ` [PATCH 1/2]: serial8250: Use native_io_delay on the x86 Simon Kagstrom
2010-03-17 13:01   ` Alan Cox
2010-03-17 14:09     ` Simon Kagstrom
2010-03-17 18:25   ` H. Peter Anvin
2010-03-17 18:36     ` Alan Cox
2010-03-17 18:43       ` H. Peter Anvin [this message]
2010-03-17 12:30 ` [PATCH 2/2]: x86 real mode: Set delay port according to kernel config Simon Kagstrom

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