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FromArnd Bergmann <>
SubjectRe: [PATCH 2/6]: powerpc/cell spidernet low watermark patch.
DateSun, 20 Aug 2006 12:03:14 +0200
On Sunday 20 August 2006 08:31, Benjamin Herrenschmidt wrote:
> > card->low_watermark->next->dmac_cmd_status |= SPIDER_NET_DESCR_TXDESFLG;
> > mb();> > card->low_watermark->dmac_cmd_status &= ~SPIDER_NET_DESCR_TXDESFLG;
> > card->low_watermark = card->low_watermark->next;
> > > > when we queue another frame for TX.> > I would have expected those to be racy vs. the hardware... what if the
> hardware is updating dmac_cmd_status just as your are trying to and the
> bit out of it ?

Right, that doesn't work. It is the only bit we use in that byte though,
so maybe it can be done with a single byte write.

	Arnd <><
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