[Intel-gfx] [PATCH v4 2/2] drm/i915: Add missing MacBook Pro models with dual channel LVDS

[Lukas Wunner]

Single channel LVDS maxes out at 112 MHz. The 15" pre-retina models
shipped with 1440x900 (106 MHz) by default or 1680x1050 (119 MHz)
as a BTO option, both versions used dual channel LVDS even though
the smaller one would have fit into a single channel.

Signed-off-by: Lukas Wunner <lukas at wunner.de>
Acked-by: Jani Nikula <jani.nikula at intel.com>
Cc: stable at vger.kernel.org
---

Notes:
    Bug report showing that the MacBookPro8,2 with 1440x900 uses dual
    channel LVDS (this lead to it being hardcoded in intel_lvds.c by
    Daniel Vetter with commit 618563e3945b9d0864154bab3c607865b557cecc):
    https://bugzilla.kernel.org/show_bug.cgi?id=42842
    
    If i915.lvds_channel_mode=2 is missing even though the machine needs
    it, every other vertical line is white and consequently, only the left
    half of the screen is visible (verified by myself on a MacBookPro9,1).
    
    Forum posting concerning a MacBookPro6,2 with 1440x900, author is
    using i915.lvds_channel_mode=2 on the kernel command line, proving
    that the machine uses dual channels:
    https://bbs.archlinux.org/viewtopic.php?id=185770
    
    Chi Mei N154C6-L04 with 1440x900 is a replacement panel for all
    MacBook Pro "A1286" models, and that model number encompasses the
    MacBookPro6,2 / 8,2 / 9,1. Page 17 of the panel's datasheet shows
    it's driven with dual channel LVDS:
    http://www.ebay.com/itm/-/400690878560
    http://www.everymac.com/ultimate-mac-lookup/?search_keywords=A1286
    http://www.taopanel.com/chimei/datasheet/N154C6-L04.pdf
    
    Those three 15" models, MacBookPro6,2 / 8,2 / 9,1, are the only
    ones with i915 graphics and dual channel LVDS, so that list should
    be complete. And the 8,2 is already in intel_lvds.c.
    
    Possible motivation to use dual channel LVDS even on the 1440x900
    models: Reduce the number of different parts, i.e. use identical
    logic boards and display cabling on both versions and the only
    differing component is the panel.

 drivers/gpu/drm/i915/intel_lvds.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index ee621e3..fbcc7df 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -813,12 +813,28 @@ static int intel_dual_link_lvds_callback(const struct dmi_system_id *id)
 static const struct dmi_system_id intel_dual_link_lvds[] = {
 	{
 		.callback = intel_dual_link_lvds_callback,
-		.ident = "Apple MacBook Pro (Core i5/i7 Series)",
+		.ident = "Apple MacBook Pro 15\" (2010)",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro6,2"),
+		},
+	},
+	{
+		.callback = intel_dual_link_lvds_callback,
+		.ident = "Apple MacBook Pro 15\" (2011)",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro8,2"),
 		},
 	},
+	{
+		.callback = intel_dual_link_lvds_callback,
+		.ident = "Apple MacBook Pro 15\" (2012)",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro9,1"),
+		},
+	},
 	{ }	/* terminating entry */
 };
 
-- 
1.8.5.2 (Apple Git-48)