| 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. |
