Messages in this thread | | | Date | Mon, 08 Aug 2022 12:06:29 +0200 | From | Paul Cercueil <> | Subject | Re: [PATCH 20/28] mfd: arizona: Remove #ifdef guards for PM related functions |
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Hi Richard,
Le lun., août 8 2022 at 10:53:54 +0100, Richard Fitzgerald <rf@opensource.cirrus.com> a écrit : > On 07/08/2022 15:52, Paul Cercueil wrote: >> Only export the arizona_pm_ops if CONFIG_PM is set, but leave the >> suspend/resume functions (and related code) outside #ifdef guards. >> >> If CONFIG_PM is not set, the arizona_pm_ops will be defined as >> "static __maybe_unused", and the structure plus all the callbacks >> will >> be automatically dropped by the compiler. >> >> The advantage is then that these functions are now always compiled >> independently of any Kconfig option, and thanks to that bugs and >> regressions are easier to catch. >> >> Signed-off-by: Paul Cercueil <paul@crapouillou.net> >> Cc: patches@opensource.cirrus.com >> --- >> drivers/mfd/arizona-core.c | 21 +++++++++++---------- >> drivers/mfd/arizona-i2c.c | 2 +- >> drivers/mfd/arizona-spi.c | 2 +- >> 3 files changed, 13 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c >> index cbf1dd90b70d..c1acc9521f83 100644 >> --- a/drivers/mfd/arizona-core.c >> +++ b/drivers/mfd/arizona-core.c >> @@ -480,7 +480,6 @@ static int wm5102_clear_write_sequencer(struct >> arizona *arizona) >> return 0; >> } >> -#ifdef CONFIG_PM >> static int arizona_isolate_dcvdd(struct arizona *arizona) > > __maybe_unused?
No need. The symbols are always referenced.
>> { >> int ret; >> @@ -742,9 +741,7 @@ static int arizona_runtime_suspend(struct device >> *dev) > > __maybe_unused? > >> return 0; >> } >> -#endif >> -#ifdef CONFIG_PM_SLEEP >> static int arizona_suspend(struct device *dev) > > __maybe_unused? > >> { >> struct arizona *arizona = dev_get_drvdata(dev); >> @@ -784,17 +781,21 @@ static int arizona_resume(struct device *dev) > > __maybe_unused? > >> return 0; >> } >> -#endif >> +#ifndef CONFIG_PM >> +static __maybe_unused >> +#endif > > No need to ifdef a __maybe_unused.
Yes, it is needed, because the symbol is conditionally exported. If !CONFIG_PM, we want the compiler to discard the dev_pm_ops and all the callbacks, hence the "static __maybe_unused". That's the same trick used in _EXPORT_DEV_PM_OPS().
(note that this patch is broken as it does not change the struct name, in the !PM case, which causes conflicts with the .h. I'll fix in v2)
>> const struct dev_pm_ops arizona_pm_ops = { >> - SET_RUNTIME_PM_OPS(arizona_runtime_suspend, >> - arizona_runtime_resume, >> - NULL) >> - SET_SYSTEM_SLEEP_PM_OPS(arizona_suspend, arizona_resume) >> - SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(arizona_suspend_noirq, >> - arizona_resume_noirq) >> + RUNTIME_PM_OPS(arizona_runtime_suspend, >> + arizona_runtime_resume, >> + NULL) >> + SYSTEM_SLEEP_PM_OPS(arizona_suspend, arizona_resume) >> + NOIRQ_SYSTEM_SLEEP_PM_OPS(arizona_suspend_noirq, >> + arizona_resume_noirq) >> }; >> +#ifdef CONFIG_PM >> EXPORT_SYMBOL_GPL(arizona_pm_ops); >> +#endif > > This ifdeffing is ugly. Why must the structure only be exported if > CONFIG_PM is set?
So that all the PM code is garbage-collected by the compiler if !CONFIG_PM.
Ideally I would use something like EXPORT_SIMPLE_DEV_PM_OPS() which would make the patch much cleaner, but it doesn't support noirq callbacks - and that's why I suggested in the cover letter that maybe a new PM macro can be added if this patch is deemed too messy.
Cheers, -Paul
>> #ifdef CONFIG_OF >> static int arizona_of_get_core_pdata(struct arizona *arizona) >> diff --git a/drivers/mfd/arizona-i2c.c b/drivers/mfd/arizona-i2c.c >> index 6d83e6b9a692..8799d9183bee 100644 >> --- a/drivers/mfd/arizona-i2c.c >> +++ b/drivers/mfd/arizona-i2c.c >> @@ -119,7 +119,7 @@ static const struct of_device_id >> arizona_i2c_of_match[] = { >> static struct i2c_driver arizona_i2c_driver = { >> .driver = { >> .name = "arizona", >> - .pm = &arizona_pm_ops, >> + .pm = pm_ptr(&arizona_pm_ops), >> .of_match_table = of_match_ptr(arizona_i2c_of_match), >> }, >> .probe = arizona_i2c_probe, >> diff --git a/drivers/mfd/arizona-spi.c b/drivers/mfd/arizona-spi.c >> index 941b0267d09d..da05b966d48c 100644 >> --- a/drivers/mfd/arizona-spi.c >> +++ b/drivers/mfd/arizona-spi.c >> @@ -282,7 +282,7 @@ static const struct of_device_id >> arizona_spi_of_match[] = { >> static struct spi_driver arizona_spi_driver = { >> .driver = { >> .name = "arizona", >> - .pm = &arizona_pm_ops, >> + .pm = pm_ptr(&arizona_pm_ops), >> .of_match_table = of_match_ptr(arizona_spi_of_match), >> .acpi_match_table = ACPI_PTR(arizona_acpi_match), >> },
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