Re: [PATCH] iio: adc: ti-ads7950: add GPIO support
From: Jonathan Cameron
Date: Mon Feb 11 2019 - 15:06:07 EST
On Sat, 9 Feb 2019 12:56:11 -0600
David Lechner <david@xxxxxxxxxxxxxx> wrote:
> On 2/9/19 11:00 AM, Jonathan Cameron wrote:
> > Nope. This is a state lock used to protect against transitions between
> > different modes of the IIO device (buffered vs polled), it
> > isn't suitable for general use.
> > The driver should be modified to handle that correctly.
> > We have iio_claim_direct_mode etc that deal with the case
> > where a device can't do certain operations whilst in buffered
> > mode. Note it can fail and should.
> > Seems there are more drivers still doing this than I thought.
> > If anyone is bored and wants to clean them out, that would be
> > most appreciated!
> > If you need locking to protect a local buffer or the device
> > state, define a new lock to do it with clearly documented
> > scope.
> Just as a reminder, there is a use case for this particular
> chip that requires buffered mode and direct mode at the same
Thanks, I had indeed forgotten that entirely.
So it should have a local lock and not take mlock explicitly at all.