On Sat, Jun 24, 2017 at 02:25:46AM +0200, Rafael Wysocki wrote: > On Wednesday, June 21, 2017 11:15:43 AM Darren Hart wrote: > > On Fri, Jun 16, 2017 at 06:40:52AM +0200, Michał Kępień wrote: > > > All ACPI device notify callbacks are invoked using acpi_os_execute(), > > > which causes the supplied callback to be queued to a static workqueue > > > which always executes on CPU 0. This means that there is no possibility > > > for any ACPI device notify callback to be concurrently executed on > > > multiple CPUs, which in the case of fujitsu-laptop means that using a > > > locked kfifo for handling hotkeys is redundant: as hotkey scancodes are > > > only pushed and popped from within acpi_fujitsu_laptop_notify(), no risk > > > of concurrent pushing and popping exists. > > > > Was the kfifo causing a problem currently or for the migration to separate > > modules? Is this purely a simplification? > > > > Rafael, the above rationale appears sound to me. Do you have any concerns? > > I actually do. > > While this is the case today, making the driver code depend on it in a hard way > sort of makes it difficult to change in the future if need be. OK, if we aren't guaranteed for this to run on CPU 0 in the future, and this will be annoying to debug if it does changes, let's skip the kfifo change. I have removed this patch, and fixed up the merge conflicts of the remaining 6 patches here: http://git.infradead.org/linux-platform-drivers-x86.git/shortlog/refs/heads/fujitsu Michal / Jonathan, would you please review and let me know if this is what you would have done / approve the rebase? Thanks, -- Darren Hart VMware Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
