[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20090908161204.GA3113@gambetta>
Date: Tue, 8 Sep 2009 16:24:34 +0000
From: Frederik Deweerdt <frederik.deweerdt@...og.eu>
To: Alan Stern <stern@...land.harvard.edu>
Cc: linux-ide@...r.kernel.org,
Kernel development list <linux-kernel@...r.kernel.org>
Subject: Re: Limiting DMA speeds for individual IDE drives
On Tue, Sep 08, 2009 at 12:03:48PM -0400, Alan Stern wrote:
> Is there any simple way to force the old IDE driver to limit the DMA
> speed for a particular device?
>
> I've got a situation where a drive claims to be capable of supporting
> UDMA/100, but it's in a noisy environment and gets lots of errors at
> that speed. I'd like to limit it to UDMA/66 or even UDMA/33.
>
> The hdparm command should be able to do this but I can't run it until
> the system has booted, by which time a bunch of CRC and possibly other
> errors have already occurred. Ideally it should be possible to limit
> the speed starting as early as device detection, but I can't find any
> way to do it. Is there support for such a thing or will I have to hack
> it in?
Does passing ide=nodma at bootime, and then having init set the DMA at
the right speed, would work?
Regards,
Frederik
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists