break;
        case 2:
        case 3:
-               /* r6xx, r7xx, evergreen, ni */
+       case 5:
+               /* r6xx, r7xx, evergreen, ni, si */
                if (rdev->family <= CHIP_RV770) {
                        args.v2.ucAction = clock_type;
                        args.v2.ulClock = cpu_to_le32(clock);   /* 10 khz */
                                dividers->vco_mode = (args.v3.ucCntlFlag &
                                                      ATOM_PLL_CNTL_FLAG_MPLL_VCO_MODE) ? 1 : 0;
                        } else {
+                               /* for SI we use ComputeMemoryClockParam for memory plls */
+                               if (rdev->family >= CHIP_TAHITI)
+                                       return -EINVAL;
                                args.v5.ulClockParams = cpu_to_le32((clock_type << 24) | clock);
                                if (strobe_mode)
                                        args.v5.ucInputFlag = ATOM_PLL_INPUT_FLAG_PLL_STROBE_MODE_EN;