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Diffstat (limited to 'Documentation/sound/oss/VIA-chipset')
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1 | Running sound cards on VIA chipsets | ||
2 | |||
3 | o There are problems with VIA chipsets and sound cards that appear to | ||
4 | lock the hardware solidly. Test programs under DOS have verified the | ||
5 | problem exists on at least some (but apparently not all) VIA boards | ||
6 | |||
7 | o VIA have so far failed to bother to answer support mail on the subject | ||
8 | so if you are a VIA engineer feeling aggrieved as you read this | ||
9 | document go chase your own people. If there is a workaround please | ||
10 | let us know so we can implement it. | ||
11 | |||
12 | |||
13 | Certain patterns of ISA DMA access used for most PC sound cards cause the | ||
14 | VIA chipsets to lock up. From the collected reports this appears to cover a | ||
15 | wide range of boards. Some also lock up with sound cards under Win* as well. | ||
16 | |||
17 | Linux implements a workaround providing your chipset is PCI and you compiled | ||
18 | with PCI Quirks enabled. If so you will see a message | ||
19 | "Activating ISA DMA bug workarounds" | ||
20 | |||
21 | during booting. If you have a VIA PCI chipset that hangs when you use the | ||
22 | sound and is not generating this message even with PCI quirks enabled | ||
23 | please report the information to the linux-kernel list (see REPORTING-BUGS). | ||
24 | |||
25 | If you are one of the tiny number of unfortunates with a 486 ISA/VLB VIA | ||
26 | chipset board you need to do the following to build a special kernel for | ||
27 | your board | ||
28 | |||
29 | edit linux/include/asm-i386/dma.h | ||
30 | |||
31 | change | ||
32 | |||
33 | #define isa_dma_bridge_buggy (0) | ||
34 | |||
35 | to | ||
36 | |||
37 | #define isa_dma_bridge_buggy (1) | ||
38 | |||
39 | and rebuild a kernel without PCI quirk support. | ||
40 | |||
41 | |||
42 | Other than this particular glitch the VIA [M]VP* chipsets appear to work | ||
43 | perfectly with Linux. | ||