Re: pci_alloc_consistent from interrupt == BAD

David S. Miller (davem@redhat.com)
Fri, 18 Jan 2002 12:38:37 -0800 (PST)


From: Gérard Roudier <groudier@free.fr>
Date: Fri, 18 Jan 2002 21:21:35 +0100 (CET)

I have noted that some ports may [ever] require pci_alloc_consistent not
to be called from interrupt context. Just I will look into this when time
will allow.

Do not bother Gerard, these ports really are broken and
pci_alloc_consistent must work from interrupts.

I am not going to ever use not cache coherent hardware, even if I am ready
to make the sym driver work reliably on such brain-dead things. Just it is
not high priority stuff for now.

Perhaps you misunderstand, it is not "lack of cache coherency" it is
"cache needs flushing around DMA transfers" and this is handled
perfectly by PCI DMA interfaces. It is nothing you should be
concerned about.
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