Re: PCI DMA to small buffers on cache-incoherent arch

From: Oliver Neukum (
Date: Mon Jun 10 2002 - 12:22:26 EST

> > So is the consensus now that in general drivers should make sure any
> > buffers passed to pci_map/unmap are aligned to SMP_CACHE_BYTES (and a
> > multiple of SMP_CACHE_BYTES in size)? In other words if a driver uses
> > an unaligned buffer it should be fixed unless we can prove (and
> > document in a comment :) that it won't cause problems on an arch
> > without cache coherency and with a writeback cache.
> And how about we don't call it SMP_CACHE_BYTES too? The processors
> where this matters certainly aren't doing SMP...

Definitely we should call it something different so we can limit it to
architectures that need it.


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This archive was generated by hypermail 2b29 : Sat Jun 15 2002 - 22:00:18 EST