Re: [PATCH v15 00/13] mux controller abstraction and iio/i2c muxes

From: Greg Kroah-Hartman
Date: Sat Jun 03 2017 - 11:38:24 EST


On Sat, Jun 03, 2017 at 07:26:27PM +0900, Greg Kroah-Hartman wrote:
> On Sun, May 14, 2017 at 09:51:03PM +0200, Peter Rosin wrote:
> > From: Peter Rosin <peda@xxxxxxxxxx>
> >
> > Hi Greg,
> >
> > Philipp found problems in v14 with using a mutex for locking that was
> > the outcome of the review for v13, so I'm now using a semaphore instead
> > of the rwsem that was in v13. That at least got rid of the scary call
> > to downgrade_write. However, I'm still unsure about what you actually
> > meant with your comment about lack of sparse markings [1]. I did add
> > __must_check to the funcs that selects the mux, but I've got this
> > feeling that this is not what you meant?
>
> I thought there was a way to mark a function as requiring a lock be held
> when it is being called. Does sparse not support that anymore?

Anyway, not a big deal. I still worry about the calls blocking when
people are not expecting them to, but it is just the nature of th api I
guess.

All now queued up, nice work, thanks for sticking with this.

greg k-h