On 12.02.2024 22:17, Bjorn Helgaas wrote: > Maybe include the reason in the subject? "Read back" is literally > what the diff says. > > On Sat, Feb 10, 2024 at 06:10:06PM +0100, Konrad Dybcio wrote: >> To ensure write completion, read the PARF_LTSSM register after setting >> the LTSSM enable bit before polling for "link up". > > The write will obviously complete *some* time; I assume the point is > that it's important for it to complete before some other event, and it > would be nice to know why that's important. Right, that's very much meaningful on non-total-store-ordering architectures, like arm64, where the CPU receives a store instruction, but that does not necessarily impact the memory/MMIO state immediately. Konrad
