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Sync with i386

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This commit is contained in:
peter 2004-08-16 22:51:13 +00:00
parent efc85186f0
commit 2800cddd5f
1 changed files with 11 additions and 3 deletions
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14
sys/amd64/isa/isa_dma.c
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@ -103,12 +103,20 @@ isa_dmainit(chan, bouncebufsize)
{
void *buf;
/*
* If a DMA channel is shared, both drivers have to call isa_dmainit
* since they don't know that the other driver will do it.
* Just return if we're already set up good.
* XXX: this only works if they agree on the bouncebuf size. This
* XXX: is typically the case since they are multiple instances of
* XXX: the same driver.
*/
if (dma_bouncebuf[chan] != NULL)
return;
#ifdef DIAGNOSTIC
if (chan & ~VALID_DMA_MASK)
panic("isa_dmainit: channel out of range");
if (dma_bouncebuf[chan] != NULL)
panic("isa_dmainit: impossible request");
#endif
dma_bouncebufsize[chan] = bouncebufsize;