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Avoid using the VGA arbiter during intel_vga_get() for iGPUs because that will clobber the VGA routing for whatever external GPU is the current VGA device. That will cause all reads from VGA memory to come back as 0xff/white, and thus we get a white rectangle on screen when the external GPU switches from vgacon to fbcon. The iGPU has the highest VGA decode priority so it will steal all VGA register accesses whenever its IO decoding is enabled. We'll only keep the IO decode enabled for a short time so hopefully we don't end up eating too many unrelated VGA register accesses. For discrete GPUs we need all the bridges to have their VGA forwarding bits correctly configured so we can't really avoid the VGA arbiter there. Although we only do this stuff on dGPUs when the VGA plane was actaully enabled, so the dGPU should be the current VGA device and thus have VGA routed to it already anyway. Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patch.msgid.link/20251208182637.334-8-ville.syrjala@linux.intel.com Acked-by: Jani Nikula <jani.nikula@intel.com>