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SCSI problems

DISCUSSION Thomas Bogendoerfer 2 participants 3 messages Sep 5, 1998 – Sep 7, 1998 1 message not in the archive MIPS

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Thomas Bogendoerfer

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#0 lore raw

I'm trying to narrow down the SCSI problems, which some people are seeing. I did some test with a DAT drive and got also problems. Right now my Indy is running with a normal kernel but with SCSI dma disabled. And I didn't see any problems. So could anybody try to start the kernel with following setup option added:

wd33c93=nodma:1

Of course this decreases the SCSI speed, but I want know, if we get rid of the problems. If I'm on the right track, I suspect some problems with DMA/cache flushing.

Thomas.

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See, you not only have to be a good coder to create a system like Linux,
you have to be a sneaky bastard too ;-)
                   [Linus Torvalds in <[email protected]>]

A message that is not in the archive (sent off-list or not yet received): [email protected]

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#2 lore raw
Quoted 3 lines · Ulf Carlsson

On Sat, 5 Sep 1998, Thomas Bogendoerfer wrote:
Which processor do you have, e.g. which dma_cache_wback_inv procedure are you making use of?

it's a R4600 with second level cache. So it should use r4k_dma_cache_wback_inv_sc(), too.

Thomas.

Signature · 3 lines
See, you not only have to be a good coder to create a system like Linux,
you have to be a sneaky bastard too ;-)
                   [Linus Torvalds in <[email protected]>]
#3 lore raw
Quoted 7 lines · Thomas Bogendoerfer
Quoted 3 lines · Ulf Carlsson

On Sat, 5 Sep 1998, Thomas Bogendoerfer wrote:
Which processor do you have, e.g. which dma_cache_wback_inv procedure are you making use of?

it's a R4600 with second level cache. So it should use r4k_dma_cache_wback_inv_sc(), too.

The R4600 _CPU_ doesn't support an l2 cache therefore the *_pc variants are being used. The l2 cache on the indy CPU module is handled by the logic on the CPU _module_; the code to deal with that is being called by the *_pc functions and is in arch/mips/sgi/kernel/indy_sc.c.

Ralf