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. Bjorn