On Mon, 18 Aug 2014 07:32:15 PM Guenter Roeck wrote: > On Tue, Aug 19, 2014 at 09:19:55AM +1000, Con Kolivas wrote: > > As a followup to this discussion: > > > > On Tue, 15 Jul 2014 08:01:13 PM Sam Asadi wrote: > > > Commit f36fdb9f0266 (i8k: Force SMM to run on CPU 0) adds support > > > for multi-core CPUs to the driver. Unfortunately, that causes it > > > to fail loading if compiled without SMP support, at least on > > > 32 bit kernels. Kernel log shows "i8k: unable to get SMM Dell > > > signature", and function i8k_smm is found to return -EINVAL. > > > > > > Testing revealed that the culprit is the missing return value check > > > of set_cpus_allowed_ptr. > > > > It appears that the original commit f36fdb9f0266 changes the affinity for > > the duration of i8k_smm function and then unconditionally reverts the > > affinity to the old cpu mask regardless of whether the function succeeds > > or fails. As this must run on CPU 0 at all times it does not make sense > > to revert the affinity at the end of the function. Proposed patch > > attached. > > Sorry, I must have missed the rest of the discussion. What problem is this > patch supposed to fix ? Or, in other words, is there a problem with the > current code ? I also don't really understand the argument above. Why does > it not make sense to revert to the original affinity ? After all, only the > SMM call must run on CPU 0. Why does it not make sense to let the rest of > the code run on another CPU ? My mistake. If only the i8k_smm function needs to run on CPU 0 then it is appropriate to return affinity to the previous CPU mask. Please disregard and apologies for the noise. Thanks, Con -- -ck _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
