On Wed Sep 2, 2026 at 5:59 AM JST, Gary Guo wrote: > In the CPU->GSP messaging path, the code reads the read pointer from GSP, > writes the command, advances the write pointer, and then notifies the GSP. > > A LOAD->STORE ordering is needed after reading the read pointer from GSP > and writing the command. Control dependency exists here which provide the > needed ordering, but it's best to avoid depending on it. > > A STORE->STORE ordering is needed after the command write and before the > write pointer advance. This is currently incorrectly done after the write > pointer advance (and before GSP notification), but this can cause issue if > GSP is still processing ring buffer, as it may observe the write pointer > advance before command write. Thus move this barrier to be before the write > pointer advance. Note that barriers are not needed between write pointer > advance and GSP notification, as MMIO accessors already carries the > required barrier. > > Signed-off-by: Gary Guo <[email protected]> > ---
Reviewed-by: Eliot Courtney <[email protected]>
