~mcf/plan9front

a00957efee9643c3b025b9d20d6ab4fc6536eb89 — Michael Forney 2 years ago 79c7e45
igfx: maintain single/double-channel LVDS mode from BIOS
1 files changed, 6 insertions(+), 1 deletions(-)

M sys/src/cmd/aux/vga/igfx.c
M sys/src/cmd/aux/vga/igfx.c => sys/src/cmd/aux/vga/igfx.c +6 -1
@@ 850,7 850,12 @@ initdpll(Igfx *igfx, int x, int freq, int port)
	dpll->ctrl.v &= ~(3<<24);
	if(port == PortLCD){
		p2 = 14;
		if(freq > 112*MHz){
		/*
		 * Use dual-channel LVDS if the display clock is
		 * outside the range of single-channel, or it was
		 * preconfigured by the BIOS.
		 */
		if(freq > 112*MHz || (igfx->lvds.v>>4 & 3) == 3){
			p2 >>= 1;
			dpll->ctrl.v |= (1<<24);
		}