Re: [PATCH RESEND] mfd: mc13xxx: Remove unneeded mc13xxx_lock/unlock

Alexander Shiyan shc_work at
Mon Dec 2 05:33:29 EST 2013


> Le 30/11/2013 06:01, Alexander Shiyan a écrit :
> > Locking is performed by regmap API so no additional locking is
> > needed. Nevertheless, keep locking in the ADC conversion routine.
> > This need for keep proper read ADC sequence when calling from adc &
> > touchscreen drivers.
> You can't do that so easily !
> Regmap only protect against concurrent access to the SPI/I2C bus, but do
> not protect the driver's internal data.
> And it does not protect against a race between concurrent access at a
> higher level :
> It's OK to do this if you are protected by a mutex, but as soon as you
> remove it you will have concurrency between two irq_unmask/irq_mask.

irq_unmask/irq_mask and some other functions can be converted to use
mc13xxx_reg_rmw. So I'll make a patch for this first.


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