| Running sound cards on VIA chipsets | |
| o There are problems with VIA chipsets and sound cards that appear to | |
| lock the hardware solidly. Test programs under DOS have verified the | |
| problem exists on at least some (but apparently not all) VIA boards | |
| o VIA have so far failed to bother to answer support mail on the subject | |
| so if you are a VIA engineer feeling aggrieved as you read this | |
| document go chase your own people. If there is a workaround please | |
| let us know so we can implement it. | |
| Certain patterns of ISA DMA access used for most PC sound cards cause the | |
| VIA chipsets to lock up. From the collected reports this appears to cover a | |
| wide range of boards. Some also lock up with sound cards under Win* as well. | |
| Linux implements a workaround providing your chipset is PCI and you compiled | |
| with PCI Quirks enabled. If so you will see a message | |
| "Activating ISA DMA bug workarounds" | |
| during booting. If you have a VIA PCI chipset that hangs when you use the | |
| sound and is not generating this message even with PCI quirks enabled | |
| please report the information to the linux-kernel list (see REPORTING-BUGS). | |
| If you are one of the tiny number of unfortunates with a 486 ISA/VLB VIA | |
| chipset board you need to do the following to build a special kernel for | |
| your board | |
| edit linux/include/asm-i386/dma.h | |
| change | |
| #define isa_dma_bridge_buggy (0) | |
| to | |
| #define isa_dma_bridge_buggy (1) | |
| and rebuild a kernel without PCI quirk support. | |
| Other than this particular glitch the VIA [M]VP* chipsets appear to work | |
| perfectly with Linux. |