在 2024-07-03星期三的 16:08 -0500,Bjorn Helgaas写道: > On Wed, Jul 03, 2024 at 04:52:30PM +0800, Jiaxun Yang wrote: > > 在2024年7月2日七月 下午6:03,Jiaxun Yang写道: > > > 在2024年7月2日七月 下午5:27,Christian König写道: > > > > Am 02.07.24 um 11:06 schrieb Icenowy Zheng: > > > > > [SNIP] However I don't think the definition of the AGP spec > > > > > could apply on all > > > > > PCI(e) implementations. The AGP spec itself don't apply on > > > > > implementations that do not implement AGP (which is the most > > > > > PCI(e) > > > > > implementations today), and it's not in the reference list of > > > > > the PCIe > > > > > spec, so it does no help on this context. > > > > No, exactly that is not correct. > > > > > > > > See as I explained the No-Snoop extension to PCIe was created > > > > to help > > > > with AGP support and later merged into the base PCIe > > > > specification. > > > > > > > > So the AGP spec is now part of the PCIe spec. > > > > Hi Bjorn & linux-pci folks, > > > > It seems like we have some disputes on interpretation pf PCIe > > specification. > > > > We are seeking your expertise on the question: Does PCIe > > specification mandate Cache coherency via snoop? > > I'm not qualified to opine on this. I'd say it's a question for the > PCI SIG protocol workgroup. https://forum.pcisig.com/ is a place to > start. Sorry for the disturbance. As individual hacker, I am not eligble of being a PCI-SIG member and join the discussion there. So I here want to ask a question as an individual hacker: what's the policy of linux-pci towards these non-coherent PCIe implementations? If the sentences of Christian is right, these implementations are just out-of-spec, should them get purged out of the kernel, or at least raising a warning that some HW won't work because of inconformant implementation? > > Bjorn