Messages in this thread | | | Date | Wed, 22 Feb 2006 23:12:00 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH] cpufrequency change on AC-Adapter Event |
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On Út 21-02-06 22:37:42, Thomas Ogrisegg wrote: > Problem Description: > Whenever the status of the AC-Adapter on my laptop changes, the CPU > frequency automatically changes as well. For example, if the AC adapter > is online my CPU has the highest frequency (3,06 GHz). When the adapter > is unplugged, the frequency automatically decreases to 1,6 GHz. However, > currently the Kernel simply doesn't notice. It looks like the system is > still running at 3,06 GHz (/proc/cpuinfo and > /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq both show that), > but it doesn't like a simple test program showed. > > My patch solves this problem: Whenever the status of the AC Adapter > changes, it calls 'cpufreq_reinit' which in turn reinits the CPUfreq > driver. > > This, of course, only works if the ACPI AC driver is compiled in. > > Signed-off-by: Thomas Ogrisegg <tom-lkml@lkml.fnord.at>
> diff -uNr -X linux-2.6.15/Documentation/dontdiff linux-2.6.15/drivers/acpi/ac.c linux-2.6.15.4/drivers/acpi/ac.c > --- linux-2.6.15/drivers/acpi/ac.c 2006-01-03 04:21:10.000000000 +0100 > +++ linux-2.6.15.4/drivers/acpi/ac.c 2006-02-19 17:50:20.000000000 +0100 > @@ -29,6 +29,7 @@ > #include <linux/types.h> > #include <linux/proc_fs.h> > #include <linux/seq_file.h> > +#include <linux/cpufreq.h> > #include <acpi/acpi_bus.h> > #include <acpi/acpi_drivers.h> > > @@ -213,6 +214,8 @@ > break; > } > > + cpufreq_reinit(); > + > return_VOID; > } >
Perhaps we need to call some notifier chain here? I think not only cpufreq is going to be interested... Pavel
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