The following patches are part of a larger series I've been working on to get vga_switcheroo working on hybrid graphics Macbooks. Some of these machines are not providing a VBT, and since the LVDS panel is connected to the discrete GPU at boot we can't get a mode for the panel during initialization. As a result the LVDS connector is not registered with DRM, and graphics switching is not possible.
These patches fix this issue by registering the connector even if we can't get a mode for the panel. If we don't have an EDID we check again from the vga_switcheroo reprobe callback.
This is working, except for the framebuffer console which isn't displaying when switched to the integrated GPU, which I still need to debug. I'm not entirely sure whether or not this is the correct approach though, so I wanted to go ahead and get some feedback on the patches now to make sure I'm on the right track.
Thanks, Seth
Andreas Heider (1): drm/i915: Add support for vga_switcheroo reprobe
Seth Forshee (4): drm/i915: separate out code to get EDID from LVDS panel drm/i915: register LVDS connector even if we can't get a panel mode drm/i915: make intel_lvds_get_edid() more robust drm/i915: check LVDS for EDID on GPU switches
drivers/gpu/drm/i915/i915_dma.c | 9 ++- drivers/gpu/drm/i915/intel_drv.h | 1 + drivers/gpu/drm/i915/intel_lvds.c | 156 +++++++++++++++++++++---------------- 3 files changed, 97 insertions(+), 69 deletions(-)