Re: [Intel-gfx] [PATCH 3/7] drm/i915: Treat PCH eDP like DP in most places

From: Keith Packard
Date: Wed Nov 02 2011 - 13:31:53 EST


On Wed, 02 Nov 2011 13:13:52 -0400, Adam Jackson <ajax@xxxxxxxxxx> wrote:

> Given the choice of trusting DPCD or the VBT, I'd definitely prefer
> DPCD.

Except that the DPCD is coded into the monitor while the VBT is done by
the platform. And, it's the platform which may neglect to connect some
of the wires. In any case, if we want to look at these values, we should
be doing it before computing the M/N ratio so that we actually set the
hardware up correctly.

Any bets on how long until we find a machine that has right value in the
VBT and the wrong one in DPCD? Or a machine with wrong values in both places?

--
keith.packard@xxxxxxxxx

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