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? There are some further context in this thread [1]. [1]: https://lore.kernel.org/all/0db974d40cd8c5dcc723d43c328bac923e0fe33a.camel@xxxxxxxxxx/ Thanks - Jiaxun > > We don't really buy this theory. > > Keyword "AGP" doesn't appear in "PCI Express Base 4.0 Base Specification" even > once. > > If PCIe is a predecessor of AGP, where does AGP specific software interface like > AGP aperture goes? PCIe GPUs are only borrowing software concepts from AGP, > but they didn't inherit any hardware properties. > > [...] >> We seem to have a misunderstanding here, this is not a software issue. >> The hardware platform is considered broken by the hardware vendor! > > It's up to the specification text to define compliance means. So far as > per analysis > from Icenowy of PCIe specification text itself it's not prohibited. > >> >> In other words people have stitched together hardware in a way which is >> not supported by the creator of that hardware. >> >> So as long as you can't convince anybody from ARM or the RISC-V team or >> whoever created that hardware to confirm that the hardware actually >> works you won't get any support for that. > > Well we are trying to support them on our own in mainline, we are not asking > for any support. > > Thanks > - Jiaxun >> >> Regards, >> Christian. > > -- > - Jiaxun -- - Jiaxun
