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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Jean Delvare <jdelvare@suse.de>
Cc: dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 1/2] drm/kms: Make i2c buses faster
Date: Fri, 21 Oct 2011 14:32:44 +0100	[thread overview]
Message-ID: <20111021143244.4d1eac1e@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <201110210908.30632.jdelvare@suse.de>

On Fri, 21 Oct 2011 09:08:30 +0200
Jean Delvare <jdelvare@suse.de> wrote:

> A udelay value of 20 leads to an I2C bus running at only 25 kbps. A
> value of 40 as the nouveau driver has is even slower at 12.5 kbps. I2C
> devices can typically operate faster than this, 50 kbps should be fine
> for all devices (and compliant devices can always stretch the clock is
> needed.)

That depends on your cable, drive and signal quality. It's not something
you just turn up because it seems a good idea. Reliability is MUCH more
important than shaving microseconds off monitor probe times.

Alan

  reply	other threads:[~2011-10-21 13:32 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-21  7:08 [PATCH 1/2] drm/kms: Make i2c buses faster Jean Delvare
2011-10-21 13:32 ` Alan Cox [this message]
2011-10-21 14:16   ` Jean Delvare
2011-10-21 18:05     ` Alex Deucher
2011-10-21 19:29       ` Jean Delvare
2011-10-22 14:38         ` Alex Deucher
2011-10-24 14:19           ` Eugeni Dodonov
  -- strict thread matches above, loose matches on Subject: below --
2012-01-28 10:07 Jean Delvare
2012-01-28 14:46 ` Alex Deucher
2012-01-29  1:26 ` Keith Packard
2012-03-21 10:45   ` Jean Delvare

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