On Mon, 21 Feb 2022, Jiaxun Yang wrote: > Commit 3d474da ("MIPS: Enforce strong ordering for MMIO accessors") Please follow the canonical commit reference format including a 12-digit hexadecimal hash reference (`scripts/checkpatch.pl' would have pointed it out). > SYNC based barrier is very heavy on Loongson and MTI cores as it will > issue a SYNC command on their bus and invalidate all present instrutions > in pipeline. We should generally avoid that. Use whatever lighterweight barrier instruction you have available for your specific platforms then that fulfills the ordering enforcement required here for your specific platforms of concern that you have identified and know well rather than across the board. The reason for this is this is an optimisation and the default barrier model needs to ensure correct execution with any implementation. Maciej