Messages in this thread | | | Date | Mon, 13 Feb 2012 11:35:46 -0500 | From | Dave Jones <> | Subject | Re: Cpufreq shutdown patch (kernel 2.6.35.3) |
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On Mon, Feb 13, 2012 at 11:28:53AM -0500, Dave Jones wrote: > On Thu, Jan 19, 2012 at 10:18:10PM +0100, N. Coesel wrote: > > > I've found a problem in drivers/cpufreq/cpufreq.c. The driver does > > not execute the exit member of the low level driver when shutting > > down for a reboot (reset). This potentially leaves the power supply > > at a too low voltage to boot the system properly. The patch below > > adds a shutdown function which executes the exit member of the low > > level driver which allows a system to be properly prepared for a reset. > > I'm curious what hardware you saw this problem on ? > > I've just seen a report on an x86 system which looks like it might > be solved by this. > https://bugzilla.redhat.com/show_bug.cgi?id=789964 > > > --- drivers/cpufreq/cpufreq.c.orig 2010-08-20 20:55:55.000000000 +0200 > > +++ drivers/cpufreq/cpufreq.c 2012-01-19 21:50:46.000000000 +0100 > > @@ -1431,11 +1431,34 @@ fail: > > return ret; > > } > > > > + > > +static int cpufreq_shutdown(struct sys_device *sysdev) > > +{ > > + struct cpufreq_policy *cpu_policy; > > + int cpu = sysdev->id; > > + int ret =0; > > + > > + if (!cpu_online(cpu)) > > + return 0; > > + > > + cpu_policy = cpufreq_cpu_get(cpu); > > + if (!cpu_policy) > > + return -EINVAL; > > + > > +// printk("cpufreq_shutdown %d \n", cpu); > > + if (cpufreq_driver->exit) > > + ret = cpufreq_driver->exit(cpu_policy); > > + > > + return ret; > > +} > > + > > + > > static struct sysdev_driver cpufreq_sysdev_driver = { > > .add = cpufreq_add_dev, > > .remove = cpufreq_remove_dev, > > .suspend = cpufreq_suspend, > > .resume = cpufreq_resume, > > + .shutdown = cpufreq_shutdown, > > }; > > I'll queue this up, with the whitespace fixed, and commented out line removed.
Except I can't of course, because we no longer have a sysdev driver since 8a25a2fd126c621f44f3aeaef80d51f00fc11639 Kay, given the subsys_interface doesn't have a shutdown method, what should this be doing ?
Dave
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