On Tue, Dec 17, 2013 at 09:12:10AM -0800, Keith Packard wrote: > We want to disable the (unused) VGA plane on the intel hardware, which > should be a simple matter of writing the vga control register. However, > in 2009 (commit 24f119c769bacac5729297b682fec7811a983cc6), that simple > code was changed to also smash the SR01 VGA register to fix "random > crash and lockups". > > When running efifb on an nVidia card, executing this store to SR01 > ends up causing the screen to go black. > > I'm not sure if this store is still required; this patch limits it to > when the intel card is primary.
The bspec still says we must assert SR01 bit5 prior to disabling the VGA plane. Perhaps the test should be whether (vga_reg & VGA_DISP_DISABLE) == 0 and do nothing if the plane is already off. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
