Symbol: NV_PBUS_DEBUG_DUALHEAD_CTL
drivers/gpu/drm/nouveau/dispnv04/dfp.c
500
nvif_mask(device, NV_PBUS_DEBUG_DUALHEAD_CTL, 1 << 31, 1 << 31);
drivers/gpu/drm/nouveau/dispnv04/dfp.c
503
nvif_mask(device, NV_PBUS_DEBUG_DUALHEAD_CTL, 1 << 31, 0);