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User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 26, 2019 at 08:48:37AM +0200, Christoph Hellwig wrote: > On Tue, Jun 25, 2019 at 09:37:22AM -0700, Mark Greer wrote: > > Yeah, the mpsc driver had lots of ugly cache related hacks because of > > cache coherency bugs in the early version of the MV64x60 bridge chips > > that it was embedded in. That chip is pretty much dead now and I've > > removed core support for it from the powerpc tree. Removing the mpsc > > driver is on my todo list but I've been busy and lazy. So, to sum it > > up, don't spend any more time worrying about it as it should be removed. > > > > I'll post a patch to do that tonight and I'm sorry for any time you've > > spent looking at it so far. > > No problem. And if future such broken chips show up we now have > support for per-device DMA coherency settings and could actually > handle it in a reaѕonably clean way. Ah, good to know - thanks. BTW, I just submitted a patch to remove the driver. Mark --