S_028800_BACKFACE_ENABLE 1894 drivers/gpu/drm/radeon/evergreend.h #define   S_028800_BACKFACE_ENABLE(x)                  (((x) & 0x1) << 7)
S_028800_BACKFACE_ENABLE 2342 drivers/gpu/drm/radeon/r600d.h #define   S_028800_BACKFACE_ENABLE(x)                  (((x) & 0x1) << 7)