[lkml]   [2002]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: PCI DMA to small buffers on cache-incoherent arch
On Mon, Jun 10, 2002 at 07:22:26PM +0200, Oliver Neukum wrote:
> > > 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.

No. We should just make it come out to a nop for arches that don't need
it. Otherwise we'll end up with ugly things like:

All over things like USB...

Tom Rini (TR1265)
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:26    [W:0.111 / U:3.944 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site