Re: screen rotation flipped in 4.8-rc

From: Srinivas Pandruvada
Date: Fri Sep 02 2016 - 18:48:13 EST


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/de80c50b2678
2ba6e899ee5a95b31b28790c940d


Thanks,
Srinivas