From: Lukas Wunner Date: Sun, 12 Apr 2015 19:10:35 +0000 (+0200) Subject: drm/i915: Assume dual channel LVDS if pixel clock necessitates it X-Git-Tag: omap-for-v4.2/omap1-v2~7^2^2~4 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6f317cfe42c9d8a7c9c1a327d2f1bcc517a3cd91;p=pandora-kernel.git drm/i915: Assume dual channel LVDS if pixel clock necessitates it Single channel LVDS maxes out at 112 MHz, anything above must be dual channel. This avoids the need to specify i915.lvds_channel_mode=2 on all 17" MacBook Pro models with i915 graphics since they had 1920x1200 (193 MHz), plus those 15" pre-retina models which had a resolution of 1680x1050 (119 MHz) as a BTO option. Source for 112 MHz limit of single channel LVDS is section 2.3 of: https://01.org/linuxgraphics/sites/default/files/documentation/ivb_ihd_os_vol3_part4.pdf v2: Avoid hardcoding 17" models by assuming dual channel LVDS if the resolution necessitates it, suggested by Jani Nikula. v3: Fix typo, thanks Joonas Lahtinen. v4: Split commit in two, suggested by Ville Syrjälä. Signed-off-by: Lukas Wunner Tested-by: Lukas Wunner Reviewed-by: Ville Syrjälä Cc: stable@vger.kernel.org [Jani: included spec reference into the commit message] Signed-off-by: Jani Nikula --- Reading git-diff-tree failed