[Intel-gfx] [PATCH] drm/i915: Reset GMBUS controller after NAK

[Jesse Barnes]

On Wed, 30 Mar 2011 17:07:11 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:

> Once a NAK has been asserted by the slave, we need to reset the GMBUS
> controller in order to continue. This is done by asserting the Software
> Clear Interrupt bit and then clearing it again to restore operations.
> 
> If we don't clear the NAK, then all future GMBUS xfers will fail,
> including DDC probes and EDID retrieval.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35781
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---

This one fixes the issue I was seeing on my HP test machine; LVDS DDC
probing seems to work ok once this fix is applied.

-- 
Jesse Barnes, Intel Open Source Technology Center