CNTXT_2_RING_BASE_LSB
gpi_write_reg(gpii, chan->ch_cntxt_base_reg + CNTXT_2_RING_BASE_LSB, ring->phys_addr);
gpi_write_reg(gpii, base + CNTXT_2_RING_BASE_LSB, lower_32_bits(ring->phys_addr));