> -----Original Message----- > From: cpufreq-owner@xxxxxxxxxxxxxxx [mailto:cpufreq-owner@xxxxxxxxxxxxxxx] > On Behalf Of Viresh Kumar > Sent: 2013年4月24日 18:15 > To: Tang Yuantian-B29983 > Cc: rjw@xxxxxxx; cpufreq@xxxxxxxxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] cpufreq: Fix the driver can not be unloaded issue > > On 24 April 2013 13:58, <Yuantian.Tang@xxxxxxxxxxxxx> wrote: > > From: Tang Yuantian <yuantian.tang@xxxxxxxxxxxxx> > > > > The driver compiled as a module can not be unloaded if there are more > > than one cpu in policy->cpus. That's caused by > > cpufreq_cpu_get() in cpufreq_add_dev_symlink(); It keep increasing the > > module reference count. > > This patch splites the module and policy reference count. It keeps the > > module reference count unchanged and uses the policy reference count > > to track the resource. > > > > Signed-off-by: Tang Yuantian <Yuantian.Tang@xxxxxxxxxxxxx> > > --- > > drivers/cpufreq/cpufreq.c | 16 +++------------- > > 1 file changed, 3 insertions(+), 13 deletions(-) > > I didn't quite get the problem you mentioned.. I haven't seen any issues > with the core as of now. > > When we unload a module we must call cpufreq_unregister_driver(), which > will eventually call subsys_interface_unregister() and so > cpufreq_remove_dev() will be called for each cpu. And so all the counts > should be fine and eventually module should get unloaded. > It happened when policy->cpus contains *MORE THEN ONE CPU*. Taking my board T4240 for example, it has 3 cluster, 8 CPUs for each cluster. The log is: # insmod ppc-corenet-cpufreq.ko ppc_corenet_cpufreq: Freescale PowerPC corenet CPU frequency scaling driver # rmmod ppc-corenet-cpufreq.ko ERROR: Module ppc_corenet_cpufreq is in use # lsmod Module Size Used by ppc_corenet_cpufreq 6542 9 # uname -a Linux T4240 3.9.0-rc1-11081-g34642bb-dirty #44 SMP Thu Apr 25 08:58:26 CST 2013 ppc64 unknown I am not using the newest kernel (since new t4240 board has not included yet), but the issue is still there. The reason is just like what I said in patch. Regards, Yuantian > -- > viresh > -- > To unsubscribe from this list: send the line "unsubscribe cpufreq" in the > body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at > http://vger.kernel.org/majordomo-info.html ?韬{.n?????%??檩??w?{.n???珉z??^n?■???h?璀?｛?夸z罐?+€?zf＂?????i?????_璁?:+v??撸?
