Re: [PATCH] rtc: hid-sensor-time: Add missing spin_lock_init

[Alexander Holler]

Am 17.01.2013 02:58, schrieb Thiago Farina:
> On Wed, Jan 16, 2013 at 11:49 PM, Axel Lin <axel.lin@xxxxxxxxxx> wrote:
> > Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
> > ---
> >   drivers/rtc/rtc-hid-sensor-time.c |    1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/rtc/rtc-hid-sensor-time.c b/drivers/rtc/rtc-hid-sensor-time.c
> > index 0438c9e..31c5728 100644
> > --- a/drivers/rtc/rtc-hid-sensor-time.c
> > +++ b/drivers/rtc/rtc-hid-sensor-time.c
> > @@ -225,6 +225,7 @@ static int hid_time_probe(struct platform_device *pdev)
> >
> >          platform_set_drvdata(pdev, time_state);
> >
> > +       spin_lock_init(&time_state->lock_last_time);
> Can you explain in the commit message why it is missing?
>
> For people not familiar with this code that isn't obvious.

Every spinlock must be initialized once (to SPIN_LOCK_UNLOCKED or by 
using spin_lock_init()). On most architectures SPIN_LOCK_UNLOCKED is 
just zero, therefor  the kzalloc of the time_state does it (which likely 
is the case why I haven't spotted any error without the initialization), 
but that doesn't isn't true for all architectures.

Regards,

Alexander

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