[PATCH RESEND v2 1/5] devm-helpers: Add resource managed version of work init

Matti Vaittinen
2021-06-08T10:09:47Z

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A few drivers which need a work-queue must cancel work at driver detach.
Some of those implement remove() solely for this purpose. Help drivers to
avoid unnecessary remove and error-branch implementation by adding managed
verision of work initialization. This will also help drivers to avoid
mixing manual and devm based unwinding when other resources are handled by
devm.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
---
include/linux/devm-helpers.h | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/include/linux/devm-helpers.h b/include/linux/devm-helpers.h
index f40f77717a24..74891802200d 100644
--- a/include/linux/devm-helpers.h
+++ b/include/linux/devm-helpers.h
@@ -51,4 +51,29 @@ static inline int devm_delayed_work_autocancel(struct device *dev,
return devm_add_action(dev, devm_delayed_work_drop, w);
}

+static inline void devm_work_drop(void *res)
+{
+ cancel_work_sync(res);
+}
+
+/**
+ * devm_work_autocancel - Resource-managed work allocation
+ * @dev: Device which lifetime work is bound to
+ * @w: Work to be added (and automatically cancelled)
+ * @worker: Worker function
+ *
+ * Initialize work which is automatically cancelled when driver is detached.
+ * A few drivers need to queue work which must be cancelled before driver
+ * is detached to avoid accessing removed resources.
+ * devm_work_autocancel() can be used to omit the explicit
+ * cancelleation when driver is detached.
+ */
+static inline int devm_work_autocancel(struct device *dev,
+ struct work_struct *w,
+ work_func_t worker)
+{
+ INIT_WORK(w, worker);
+ return devm_add_action(dev, devm_work_drop, w);
+}
+
#endif
--
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 =]

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