Hello, On 20/05/2022 23:33:47+0900, Tetsuo Handa wrote: > Flushing system-wide workqueues is dangerous and will be forbidden. > Replace system_wq with local rtc_wq. > > While we are at it, remove unused rtc_dev_exit(). > > Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@xxxxxxxxxxxxxxxxxxx > Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > --- > Changes in v3: > Fix build error. > Forgot to replace flush_scheduled_work(). > > Changes in v2: > Remove unused rtc_dev_exit(). > > Since rtc_dev_init() is built into vmlinux, there is no point with > recovery. > > This patch blindly converts schedule_work() into queue_work() within > drivers/rtc/dev.c, based on an assumption that none of work items > outside of drivers/rtc/dev.c needs to be handled by rtc_wq. > Did I convert correctly? > Yes and no, this could be a bit more clever and create the workqueue only for the devices that actually need it. I worked on something after seeing your first email a while ago but I needed more time to test it. > drivers/rtc/dev.c | 18 ++++++++---------- > drivers/rtc/rtc-core.h | 5 ----- > 2 files changed, 8 insertions(+), 15 deletions(-) > > diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c > index 69325aeede1a..a7346f03a5b2 100644 > --- a/drivers/rtc/dev.c > +++ b/drivers/rtc/dev.c > @@ -17,6 +17,7 @@ > #include "rtc-core.h" > > static dev_t rtc_devt; > +static struct workqueue_struct *rtc_wq; > > #define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */ > > @@ -62,7 +63,7 @@ static void rtc_uie_task(struct work_struct *work) > rtc->uie_timer_active = 1; > rtc->uie_task_active = 0; > add_timer(&rtc->uie_timer); > - } else if (schedule_work(&rtc->uie_task) == 0) { > + } else if (queue_work(rtc_wq, &rtc->uie_task) == 0) { > rtc->uie_task_active = 0; > } > spin_unlock_irq(&rtc->irq_lock); > @@ -78,7 +79,7 @@ static void rtc_uie_timer(struct timer_list *t) > spin_lock_irqsave(&rtc->irq_lock, flags); > rtc->uie_timer_active = 0; > rtc->uie_task_active = 1; > - if ((schedule_work(&rtc->uie_task) == 0)) > + if (queue_work(rtc_wq, &rtc->uie_task) == 0) > rtc->uie_task_active = 0; > spin_unlock_irqrestore(&rtc->irq_lock, flags); > } > @@ -96,7 +97,7 @@ static int clear_uie(struct rtc_device *rtc) > } > if (rtc->uie_task_active) { > spin_unlock_irq(&rtc->irq_lock); > - flush_scheduled_work(); > + flush_workqueue(rtc_wq); > spin_lock_irq(&rtc->irq_lock); > } > rtc->uie_irq_active = 0; > @@ -119,7 +120,7 @@ static int set_uie(struct rtc_device *rtc) > rtc->stop_uie_polling = 0; > rtc->oldsecs = tm.tm_sec; > rtc->uie_task_active = 1; > - if (schedule_work(&rtc->uie_task) == 0) > + if (queue_work(rtc_wq, &rtc->uie_task) == 0) > rtc->uie_task_active = 0; > } > rtc->irq_data = 0; > @@ -562,13 +563,10 @@ void __init rtc_dev_init(void) > { > int err; > > + rtc_wq = alloc_workqueue("rtc_wq", 0, 0); > + BUG_ON(!rtc_wq); > + > err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc"); > if (err < 0) > pr_err("failed to allocate char dev region\n"); > } > - > -void __exit rtc_dev_exit(void) > -{ > - if (rtc_devt) > - unregister_chrdev_region(rtc_devt, RTC_DEV_MAX); This is very unrelated and should be in a different patch. > -} > diff --git a/drivers/rtc/rtc-core.h b/drivers/rtc/rtc-core.h > index 0abf98983e13..4b10a1b8f370 100644 > --- a/drivers/rtc/rtc-core.h > +++ b/drivers/rtc/rtc-core.h > @@ -2,7 +2,6 @@ > #ifdef CONFIG_RTC_INTF_DEV > > extern void __init rtc_dev_init(void); > -extern void __exit rtc_dev_exit(void); > extern void rtc_dev_prepare(struct rtc_device *rtc); > > #else > @@ -11,10 +10,6 @@ static inline void rtc_dev_init(void) > { > } > > -static inline void rtc_dev_exit(void) > -{ > -} > - > static inline void rtc_dev_prepare(struct rtc_device *rtc) > { > } > -- > 2.34.1 > > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
