SDMA0_GFX_RB_WPTR
reg = SDMA0_GFX_RB_WPTR + SDMA0_REGISTER_OFFSET;
reg = SDMA0_GFX_RB_WPTR + SDMA1_REGISTER_OFFSET;
WREG32(SDMA0_GFX_RB_WPTR + reg_offset, 0);
WREG32(SDMA0_GFX_RB_WPTR + reg_offset, ring->wptr << 2);
reg = SDMA0_GFX_RB_WPTR + SDMA0_REGISTER_OFFSET;
reg = SDMA0_GFX_RB_WPTR + SDMA1_REGISTER_OFFSET;