Re: screen rotation flipped in 4.8-rc

[Bastien Nocera <hadess@hadess.net>]

On Fri, 2016-09-02 at 15:48 -0700, Srinivas Pandruvada wrote:
> On Tue, 2016-08-30 at 22:42 +0000, Pandruvada, Srinivas wrote:
> > Hi All,
> > 
> > I observed that using iio-sensor-proxy.service, the auto screen
> > rotation flipped on my laptop (Normal -> vertical, vertical-
> > >normal)
> > using kernel v4.8.
> > 
> > Anyone else has seen this?
> > 
> > I did a bisect and found a commit, which I am not sure how can it
> > impact.
> > 
> > 
> > commit 703b5faf22fbddf984a361e6555f3a03fdba63d9
> > Author: George Spelvin <linux@sciencehorizons.net>
> > Date:   Fri Jun 10 00:22:12 2016 -0400
> > 
> [...]
> 
> It turns out to be some assumption user space program is making about
> the traversing directory using glib call g_dir_read_name(). 
> 
> With the commit 703b5faf22fbddf984a361e6555f3a03fdba63d9
> (fs/dcache.c:
> Save one 32-bit multiply in dcache lookup)
>  in kernel 4.8-rc, somehow the order is changed (so the in_accel_y
> was
> appearing before in_accel_x )
> 
> I modified user space program to use correct iio scan element index
> to
> determine byte offset instead depending on the glib_dir_read_name,
> which doesn't guarantee any order.
> 
> I sent a pull request to author of iio-sensor-proxy to review.
> 
> Hadess,
> 	Please look.
> 
> https://github.com/hadess/iio-sensor-proxy/pull/99/commits/de80c50b26
> 78
> 2ba6e899ee5a95b31b28790c940d

I fixed it up (styling, and commit message) and merged this.

Note that there might be other problems in this particular piece of
code, that comes from the original Peter F. Patel-Schneider's helper
code for the Lenovo Yoga laptops (and based on 8-year old code from
Jonathan Cameron himself ;)

I'll make a release soonish to include this fix.

Cheers