Comment 42 for bug 1487168

only virtualbox debug log can provide debug info about why emulated ich controller support multi channel

               case GLOB_CNT:
1470 /* Global Control */
1471 *pu32 = pThis->glob_cnt;
1472 LogFlowFunc(("glob_cnt -> %#x\n", *pu32));
1473 break;
1474 case GLOB_STA:
1475 /* Global Status */
1476 *pu32 = pThis->glob_sta | GS_S0CR;
1477 LogFlowFunc(("glob_sta -> %#x\n", *pu32));
1478 break;

1600 case GLOB_CNT:
1601 /* Global Control */
1602 if (u32 & GC_WR)
1603 ichac97WarmReset(pThis);
1604 if (u32 & GC_CR)
1605 ichac97ColdReset(pThis);
1606 if (!(u32 & (GC_WR | GC_CR)))
1607 pThis->glob_cnt = u32 & GC_VALID_MASK;
1608 LogFlowFunc(("glob_cnt <- %#x (glob_cnt %#x)\n", u32, pThis->glob_cnt));
1609 break;
1610 case GLOB_STA:
1611 /* Global Status */
1612 pThis->glob_sta &= ~(u32 & GS_WCLEAR_MASK);
1613 pThis->glob_sta |= (u32 & ~(GS_WCLEAR_MASK | GS_RO_MASK)) & GS_VALID_MASK;
1614 LogFlowFunc(("glob_sta <- %#x (glob_sta %#x)\n", u32, pThis->glob_sta));
1615 break;

https://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/tree/sound/pci/intel8x0.c