On 23/02/2024 15:03, Mrinmay Sarkar wrote: > Due to some hardware changes, SA8775P has set the NO_SNOOP attribute > in its TLP for all the PCIe controllers. NO_SNOOP attribute when set, > the requester is indicating that there no cache coherency issues exit > for the addressed memory on the host i.e., memory is not cached. But > in reality, requester cannot assume this unless there is a complete > control/visibility over the addressed memory on the host. > > And worst case, if the memory is cached on the host, it may lead to > memory corruption issues. It should be noted that the caching of memory > on the host is not solely dependent on the NO_SNOOP attribute in TLP. > > So to avoid the corruption, this patch overrides the NO_SNOOP attribute > by setting the PCIE_PARF_NO_SNOOP_OVERIDE register. This patch is not > needed for other upstream supported platforms since they do not set > NO_SNOOP attribute by default. > > This series is to enable cache snooping logic in both RC and EP driver > and add the "dma-coherent" property in dtsi to support cache coherency > in SA8775P platform. Please confirm that your patchset passes 100% dtbs_check. Best regards, Krzysztof
