The pre-retina MacBook Pro uses an LVDS panel and a gmux controller to switch the panel between its two GPUs. The panel mode in VBIOS is notoriously bogus on these machines and some models have no VBIOS at all, so the inactive GPU cannot set up its LVDS output. Extend vga_switcheroo to support switching only the DDC lines. Introduce a drm_get_edid_switcheroo() helper which uses this feature. Amend i915, nouveau and radeon to call it for LVDS connectors. This only enables EDID probing on the pre-retina MBP (2008 - 2013), and only under the condition that apple-gmux loads before the DRM drivers. Later patches will address reprobing of the DRM drivers if apple-gmux loads late. The retina MBP (2012 - present) uses eDP and is apparently not capable of switching AUX separately from the main link. This will also be addressed in later patches. Previous installments: v1: http://lists.freedesktop.org/archives/dri-devel/2015-April/081515.html v2: http://lists.freedesktop.org/archives/dri-devel/2015-August/088156.html Changes since v2: * Previously the DDC locking happened in drm_get_edid() and thus was done for all DRM drivers, regardless if they are ever used on muxed machines. Now this is moved to a separate helper which is only called by relevant drivers and only for LVDS connectors. (Suggested by Thierry Reding and seconded by Alex Deucher and Daniel Vetter.) * Squashed commits, overhauled locking, added kernel-doc for new public functions and locks. (Suggested by Daniel Vetter.) Thanks a lot to the reviewers and testers for your valuable feedback. Lukas Wunner (6): vga_switcheroo: Add support for switching only the DDC apple-gmux: Add switch_ddc support drm/edid: Switch DDC when reading the EDID drm/i915: Switch DDC when reading the EDID drm/nouveau: Switch DDC when reading the EDID drm/radeon: Switch DDC when reading the EDID drivers/gpu/drm/drm_edid.c | 26 ++++++++ drivers/gpu/drm/i915/intel_lvds.c | 3 +- drivers/gpu/drm/nouveau/nouveau_connector.c | 13 +++- drivers/gpu/drm/radeon/radeon_connectors.c | 4 ++ drivers/gpu/vga/vga_switcheroo.c | 98 ++++++++++++++++++++++++++++- drivers/platform/x86/apple-gmux.c | 23 +++++++ include/drm/drm_crtc.h | 2 + include/linux/vga_switcheroo.h | 9 +++ 8 files changed, 173 insertions(+), 5 deletions(-) -- 1.8.5.2 (Apple Git-48) _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
