Re: Reproducible crash under 2.1.86 [solved and fixed]

Andrea Arcangeli (arcangeli@mbox.queen.it)
Wed, 18 Feb 1998 12:21:43 +0100 (CET)


On Wed, 18 Feb 1998, Alan Cox wrote:

>Its always hard to tell. You may want to see if instead of fixing the cause
>you can fix the problem. Put the dma calls back in but add some check code
>to make sure no DMA handling functions are getting re-entered in error. Also

What do you mean with "re-entered in error"?

>see if putting udelay(2) between each write to the DMA controller makes any
>difference.

Yesterday I tried to put udelay(1) at top of disable_dma() and make no
differences. Now I tried to put udelay(2000) at top of each function in
dma.h and the lock happen as usual. udelay(20) or (200) give the same resutl.
The lock is not related to I/O port access speed, but is a reproducible logic
problem.

I tried also to check the output of get_dma_residue() and its retval seems
completly unrelated to the lock.

Fell free to send me patches. Now with my first two patch the
soundcard works fine.

Should I replace my motherboard again?

Andrea[s] Arcangeli

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