On Monday 09 May 2016 16:37:01 Juergen Gross wrote: > On 21/04/16 15:27, Pali Rohár wrote: > > On Thursday 21 April 2016 15:12:52 Juergen Gross wrote: > >> On 21/04/16 12:57, Pali Rohár wrote: > >>> On Tuesday 05 April 2016 21:31:52 Pali Rohár wrote: > >>>> On Tuesday 05 April 2016 16:54:14 Guenter Roeck wrote: > >>>>> On Tue, Apr 05, 2016 at 07:10:07AM +0200, Juergen Gross wrote: > >>>>>> Use the smp_call_on_cpu() function to call system management > >>>>>> mode on cpu 0. > >>>>>> Make call secure by adding get_online_cpus() to avoid e.g. suspend > >>>>>> resume cycles in between. > >>>>>> > >>>>>> Signed-off-by: Juergen Gross <jgross@xxxxxxxx> > >>>>>> --- > >>>>>> V4: add call to get_online_cpus() > >>>>> > >>>>> Pali, any chance to test this ? > >>>> > >>>> I can test it, but just on machine where (probably) smm calls can be > >>>> send from any cpu... Need some time for testing and I believe I can do > >>>> that at the end of the week. > >>> > >>> Sorry I had absolutely no more free time last weekend :-( And same > >>> prediction is for this weekend and also next one... > >> > >> Pali, I've got a Dell laptop (Latitude E6440) here. Would this device be > >> okay for a test? > > > > Hi! > > > > Proper regression test should check if this patch does not break any > > function or drivers dependent on dcdbas.ko. And should be done on both > > notebook devices: which needs to issue that smm call on cpu 0 and also > > on which it is not needed. > > Hmm, couldn't get one which needs smm to be called on cpu 0. > OTOH I've done various tests and added a printk() in raise_smm() > and i8k_smm_func() issuing the cpu number it was called on. Understood, those machines are old and probably rare now. > > Some notebooks which needs smm call to issued from cpu 0 can be found in > > git commit messages of i8k, dell-laptop or dcdbas kernel drivers. > > > >> What would you do for testing? In case you can give me > >> some hints how to do a sensible test I'd do it. > > > > Test e.g. dell-laptop.ko driver. It provides /sys interface for changing > > keyboard backlight or changing rfkill switches (bluetooth wifi). > > Done. > > > Also test tools from libsmbios (userspace) package. > > Done. > > > There must be no difference in output/functionality with or without your > > patches. > > Verified. > > >> I've verified by adding a printk() to smp_call_on_cpu() that at least > >> one of the modified drivers has been used during system boot. > > > > Also you can patch i8k/dcdbas smm function to print cpu number on which > > is code running (to verify that it was really called on cpu 0 as > > needed). > > Done. > > I tested suspend/resume, too, as adding get_online_cpus() might have > changed behavior. Worked like a charm. :-) Ok, I think this should be enough. You can add my Acked-by. -- Pali Rohár pali.rohar@xxxxxxxxx _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
