On Mon, 07 Jun 2021 05:25:50 +0200,
Viresh Kumar wrote:
>
> On 04-06-21, 12:05, kyle.meyer@xxxxxxx wrote:
> > From: Kyle Meyer <kyle.meyer@xxxxxxx>
> >
> > acpi-cpufreq is loaded without performing initialization when a cpufreq
> > driver exists.
> >
> > If initialization didn't occur then skip cleanup in acpi_cpufreq_exit().
> > This prevents unnecessary freeing and unregistering when the module is
> > unloaded.
> >
> > Reported-by: Takashi Iwai <tiwai@xxxxxxxx>
> > Signed-off-by: Kyle Meyer <kyle.meyer@xxxxxxx>
> > ---
> > drivers/cpufreq/acpi-cpufreq.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> > index 7e7450453714..8d425f14c267 100644
> > --- a/drivers/cpufreq/acpi-cpufreq.c
> > +++ b/drivers/cpufreq/acpi-cpufreq.c
> > @@ -1042,8 +1042,19 @@ static int __init acpi_cpufreq_init(void)
> >
> > static void __exit acpi_cpufreq_exit(void)
> > {
> > + const char *current_driver;
> > +
> > pr_debug("%s\n", __func__);
> >
> > + /*
> > + * If another cpufreq_driver was loaded, preventing acpi-cpufreq from
> > + * registering, there's no need to unregister it.
> > + */
> > + current_driver = cpufreq_get_current_driver();
> > + if (!current_driver ||
> > + strncmp(current_driver, acpi_cpufreq_driver.name, strlen(acpi_cpufreq_driver.name)))
> > + return;
> > +
> > acpi_cpufreq_boost_exit();
> >
> > cpufreq_unregister_driver(&acpi_cpufreq_driver);
>
> Looks like some misunderstanding here, this shouldn't happen. If
> initialization didn't occur, then exit shall never be called.
The missing key information is that it's a fix for the recent change
for 5.14, i.e.
Fixes: c1d6d2fd2f64 ("cpufreq: acpi-cpufreq: Skip initialization if cpufreq driver is present")
The change made the module left even if it exits before registering
the cpufreq driver object.
Takashi
