On Wed, 19 May 2010 23:52:26 +1000 Nick Piggin <npiggin@xxxxxxx> wrote: > On Wed, May 19, 2010 at 03:44:30PM +0200, Johannes Weiner wrote: > > On Wed, May 19, 2010 at 11:36:56PM +1000, Nick Piggin wrote: > > > On Wed, May 19, 2010 at 02:17:47PM +0100, David Woodhouse wrote: > > > > > > > > The 'cacheline aligned' misconception did manage to get into the ad7877 > > > > driver in commit 3843384a though -- it now uses ____cacheline_aligned > > > > instead of __attribute__((__aligned__(ARCH_KMALLOC_MINALIGN))) as it > > > > should. > > > > > > OK so long as there is not a "must be cacheline aligned" requirement. > > > Your proposal for a __dma_aligned attribute in an arch header looks > > > like a good idea there. > > > > Would you happen to know of other potential users? At this point I'd > > much rather just allocate the buffers dynamically and hide the issue > > nicely behind kmalloc(). > > I don't think we need to hide the fact that some platforms have > specific alignment restrictions for DMA. So if any drivers make use > of the alignment, I see no problem with __dma_aligned. IIRC, such was proposed several times: http://www.mail-archive.com/linux-scsi@xxxxxxxxxxxxxxx/msg12633.html I guess that we agreed that it's better to tell driver writers to just use kmalloc. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
