| Message ID | 20220308154425.296308-1-linus.walleij@linaro.org |
|---|---|
| State | Accepted |
| Commit | c22fca40522e2be8af168f3087d87d85e404ea72 |
| Headers | show |
| Series | power: ab8500_chargalg: Use CLOCK_MONOTONIC | expand |
Hi, On Wed, Mar 09, 2022 at 06:45:59AM +0000, Vaittinen, Matti wrote: > On 3/8/22 17:44, Linus Walleij wrote: > > The HRTimer in the AB8500 charging code is using CLOCK_REALTIME > > to set an alarm some hours forward in time +/- 5 min for a safety > > timer. > > > > I have observed that this will sometimes fire sporadically > > early when charging a battery with the result that > > charging stops. > > > > As CLOCK_REALTIME can be subject to adjustments of time from > > sources such as NTP, this cannot be trusted and will likely > > for example fire events if the clock is set forward some hours > > by say NTP. > > > > Use CLOCK_MONOTONIC as indicated in other instances and the > > problem goes away. Also initialize the timer to REL mode > > as this is what will be used later. > > > > Fixes: 257107ae6b9b ("ab8500-chargalg: Use hrtimer") > > Cc: Lee Jones <lee.jones@linaro.org> > > Suggested-by: Matti Vaittinen <mazziesaccount@gmail.com> > > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > > FWIW: > Reviewed-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Thanks, queued. -- Sebastian
diff --git a/drivers/power/supply/ab8500_chargalg.c b/drivers/power/supply/ab8500_chargalg.c index 20d6b29cc9e2..c345d5e99118 100644 --- a/drivers/power/supply/ab8500_chargalg.c +++ b/drivers/power/supply/ab8500_chargalg.c @@ -1780,11 +1780,11 @@ static int ab8500_chargalg_probe(struct platform_device *pdev) psy_cfg.drv_data = di; /* Initilialize safety timer */ - hrtimer_init(&di->safety_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS); + hrtimer_init(&di->safety_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); di->safety_timer.function = ab8500_chargalg_safety_timer_expired; /* Initilialize maintenance timer */ - hrtimer_init(&di->maintenance_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS); + hrtimer_init(&di->maintenance_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); di->maintenance_timer.function = ab8500_chargalg_maintenance_timer_expired;
The HRTimer in the AB8500 charging code is using CLOCK_REALTIME to set an alarm some hours forward in time +/- 5 min for a safety timer. I have observed that this will sometimes fire sporadically early when charging a battery with the result that charging stops. As CLOCK_REALTIME can be subject to adjustments of time from sources such as NTP, this cannot be trusted and will likely for example fire events if the clock is set forward some hours by say NTP. Use CLOCK_MONOTONIC as indicated in other instances and the problem goes away. Also initialize the timer to REL mode as this is what will be used later. Fixes: 257107ae6b9b ("ab8500-chargalg: Use hrtimer") Cc: Lee Jones <lee.jones@linaro.org> Suggested-by: Matti Vaittinen <mazziesaccount@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- drivers/power/supply/ab8500_chargalg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)