On Mon, 04 May 2015, Lukas Wunner <lukas@xxxxxxxxx> wrote: > 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@xxxxxxxxx> > Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Both pushed to drm-intel-fixes, with the notes moved into the commit messages for posterity. There'll be others doing archeology on this! ;) Thanks for the patches and review. BR, Jani. > --- > > 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) > -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
