Re: [RFC PATCH 0/7] Add managed version of delayed work init

[mark gross <mgross@linux.intel.com>]

On Sat, Feb 13, 2021 at 01:58:17PM +0200, Matti Vaittinen wrote:
> It's not rare that device drivers need delayed work.
> It's not rare that this work needs driver's data.
> 
> Often this means that driver must ensure the work is not queued when
> driver exits. Usually this is done by ensuring new work is not added and
> then calling cancel_delayed_work_sync() at remove(). In many cases this
> may also require cleanup at probe error path - which is easy to forget.
> 
> It might be helpful for (a) few drivers if there was a work init
 why the (a) and not just a?

> function which would ensure cancel_delayed_work_sync() is called at
> driver exit. So this series implements one on top of devm and replaces
> the obvious cases where only thing remove call-back in a driver does is
> cancelling the work. There might be other cases where we could switch
> more than just work cancellation to use managed version and thus get rid
> of remove.
> 
> Main reson why this is RFC is that I had hard time deciding where this
> function should be introduced. It's not nice to include all device stuff
> in workqueue - because many workqueue users are not interested in
> devices. In same way, not all of the devices are interested in WQs.
> OTOH, adding own file just for this sounds like an overkill.
s/own/one

--mark

> 
> This time I decided that it is more correct that devices use WQs than
> that WQs use devices. Hence the function is introduced in
> include/linux/device.h and drivers/base/devres.c
> 
> --
> 
> Matti Vaittinen (7):
>   drivers: base: Add resource managed version of delayed work init
>   extconn: Clean-up few drivers by using managed work init
>   hwmon: raspberry-pi: Clean-up few drivers by using managed work init
>   platform/x86: gpd pocket fan: Clean-up by using managed work init
>   power: supply: Clean-up few drivers by using managed work init
>   regulator: qcom_spmi-regulator: Clean-up by using managed work init
>   watchdog: retu_wdt: Clean-up by using managed work init
> 
>  drivers/base/devres.c                        | 33 ++++++++++++++++++++
>  drivers/extcon/extcon-gpio.c                 | 14 ++-------
>  drivers/extcon/extcon-intel-int3496.c        | 15 ++-------
>  drivers/extcon/extcon-palmas.c               | 16 +++-------
>  drivers/extcon/extcon-qcom-spmi-misc.c       | 16 +++-------
>  drivers/hwmon/raspberrypi-hwmon.c            | 16 +++-------
>  drivers/platform/x86/gpd-pocket-fan.c        | 16 +++-------
>  drivers/power/supply/axp20x_usb_power.c      | 15 +++------
>  drivers/power/supply/bq24735-charger.c       | 17 +++-------
>  drivers/power/supply/ltc2941-battery-gauge.c | 19 ++++-------
>  drivers/power/supply/sbs-battery.c           | 15 +++------
>  drivers/regulator/qcom_spmi-regulator.c      | 33 +++++---------------
>  drivers/watchdog/retu_wdt.c                  | 21 +++----------
>  include/linux/device.h                       |  5 +++
>  14 files changed, 95 insertions(+), 156 deletions(-)
> 
> 
> base-commit: 92bf22614b21a2706f4993b278017e437f7785b3
> -- 
> 2.25.4
> 
> 
> -- 
> Matti Vaittinen, Linux device drivers
> ROHM Semiconductors, Finland SWDC
> Kiviharjunlenkki 1E
> 90220 OULU
> FINLAND
> 
> ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
> Simon says - in Latin please.
> ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
> Thanks to Simon Glass for the translation =]