From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Grundler Date: Tue, 26 Oct 2004 18:12:58 +0000 Subject: Re: ia64 implementation of lib/iomap.c Message-Id: <20041026181258.GH2728@cup.hp.com> List-Id: References: <16759.51459.598187.91726@napali.hpl.hp.com> In-Reply-To: <16759.51459.598187.91726@napali.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Tue, Oct 26, 2004 at 10:49:07AM -0700, Jesse Barnes wrote: > What about the relaxed read then? Should we have ioread_relaxed? > I thought we had agreed that it was easier to assume relaxed semantics > for ioread and add a dma_sync interface. I would expect that requires fixing PCI drivers that depend on it. Adding a dma_sync interface would probably make it easier to support non-coherent (DMA and CPU caches are not coherent) platforms. > Since PCI-X and PCI-Express have optional relaxed semantics that > might make sense... Jesse, you keep mixing up PCI-X Relaxed Ordering with readX() interface and the two are NOT (directly) related. The device driver can enable PCI-X Relaxed Ordering hints in general. But the IO device controls "RO" hint use on individual bus transactions it masters. I'm not sure about PCI-Express (whole new bus protocol). grant