drm/i915: Fix detection for a CMP-V PCH

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According to internal documents I found for CMP PCHs the PCI ID 0xA3C1
belongs to a CMP-V chipset. Based on the same docs the programming of
the PCH is compatible with that of KBP. Fix up my previous wrong
assumption accordingly using the SPT programming which in turn is the
basis for KBP.

The original bug reporter verified that this is the correct PCH
identification (the only way we'll program valid DDC pin-pair values to
the GMBUS register) and the Windows team uses the same identification
(that is using the KBP programming model for this PCH).

I filed the necessary Bspec update requests (BSpec/33734).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112051
Fixes: 37c92dc303 ("drm/i915: Add new CNL PCH ID seen on a CML platform")
Reported-and-tested-by: Cyrus <cyrus.lien@canonical.com>
Cc: Cyrus <cyrus.lien@canonical.com>
Cc: Timo Aaltonen <tjaalton@ubuntu.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191112104608.24587-1-imre.deak@intel.com
(cherry picked from commit 50a5065f44)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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This commit is contained in:

Imre Deak 2019-11-12 12:46:08 +02:00 • committed by Joonas Lahtinen

parent 36104fcf8f

commit 5d77aa07bd

2 changed files with 6 additions and 2 deletions

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6

drivers/gpu/drm/i915/intel_pch.c

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2

drivers/gpu/drm/i915/intel_pch.h

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