| Message ID | 20210604170500.46875-1-kyle.meyer@hpe.com |
|---|---|
| State | New |
| Headers | show |
| Series | acpi-cpufreq: Skip cleanup if initialization didn't occur | expand |
On 04-06-21, 12:05, kyle.meyer@hpe.com wrote: > From: Kyle Meyer <kyle.meyer@hpe.com> > > 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@suse.com> > Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com> > --- > 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.
On 07-06-21, 09:13, Takashi Iwai wrote: > 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. The original patch looks buggy to me, I was never able to review it :( I have replied on the original thread instead. -- viresh
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);