On Thu, Apr 04, 2019 at 05:52:35PM +0100, John Garry wrote: [ ... ] > >> > >>Note that the f71805f driver does not call request_{muxed_}region(), as it > >>should. > >> > > Hi Guenter, > > >... which is the real problem, one that is not solved by this patch. This may > >result in parallel and descructive accesses if there is another device on the > >LPC bus, and another driver accessing that device. Personally I'd rather have > >request_muxed_region() added to the f71805f driver. > > Right, we should and will still fix f71805f. If you recall, I did have the > f71805f fix in the v1 series, but you committed that it was orthogonal, so I > decided to take it out of this work for now. > > And even if we fix up f71805f and other known drivers which don't call > request_muxed_region(), we still need to police against these rogue > accesses, which is what this patch attempts to do. > Do we ? I am personally not convinced that LPC accesses _have_ to occur through PCI on any given system. I won't object to this series of patches - not my area. I do mind, though, if one of the drivers I am responsible for is cited as reason or argument for this series. I would prefer for those drivers to get fixed. Guenter