TU_SIZE_MASK
m_n->tu = REG_FIELD_GET(TU_SIZE_MASK, intel_de_read(display, data_m_reg)) + 1;
#define TU_SIZE(x) REG_FIELD_PREP(TU_SIZE_MASK, (x) - 1) /* default size 64 */
intel_de_read(display, PIPE_DATA_M1(display, pipe)) & TU_SIZE_MASK);
intel_de_read(display, PIPE_DATA_M1(display, pipe)) & TU_SIZE_MASK);
intel_de_read(display, PIPE_DATA_M1(display, pipe)) & TU_SIZE_MASK);