On Wed, Mar 22, 2017 at 03:30:29PM +0000, Ard Biesheuvel wrote: > On UEFI systems, the PCI subsystem is enumerated by the firmware, > and if a graphical framebuffer is exposed by a PCI device, its base > address and size are exposed to the OS via the Graphics Output > Protocol (GOP). > > On arm64 PCI systems, the entire PCI hierarchy is reconfigured from > scratch at boot. This may result in the GOP framebuffer address to > become stale, if the BAR covering the framebuffer is modified. This > will cause the framebuffer to become unresponsive, and may in some > cases result in unpredictable behavior if the range is reassigned to > another device. Hm, commit message seems to indicate the issue is restricted to arm64, yet there's no IS_ENABLED(ARM64) to constrain the added code to that arch? > +DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, efifb_fixup_resources); Maybe this can be constrained to PCI_BASE_CLASS_DISPLAY? Thanks, Lukas