Re: screen rotation flipped in 4.8-rc

From: Bastien Nocera
Date: Tue Sep 06 2016 - 08:25:58 EST


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@xxxxxxxxxxxxxxxxxxx>
> > Date:ÂÂÂFri 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().Â
>
> With the commit 703b5faf22fbddf984a361e6555f3a03fdba63d9
> (fs/dcache.c:
> Save one 32-bit multiply in dcache lookup)
> Âin 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 originalÂPeter 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