[PATCH 4/7 v6] drm/i915/intel_i2c: use WAIT cycle, not STOP

Chris Wilson chris at chris-wilson.co.uk
Wed Mar 28 11:48:51 PDT 2012


On Thu, 29 Mar 2012 02:26:36 +0800, Daniel Kurtz <djkurtz at chromium.org> wrote:
> The i915 is only able to generate a STOP cycle (i.e. finalize an i2c
> transaction) during a DATA or WAIT phase.  In other words, the
> controller rejects a STOP requested as part of the first transaction in a
> sequence.

The original docs have "this can only cause a STOP to be generated if a
GMBUS cycle is generated, the GMBUS is currently in a data phase, or it
is in a WAIT phase."

So from that it seems STOP | INDEX? | WAIT is always a valid
combination and is explicitly listed in the register set.

I defer to actual testing though ;)
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre


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