Tzung-Bi Shih f07980d4ed drm/mediatek: fix race condition for HDMI jack status reporting
hdmi_conn_detect and mtk_hdmi_audio_hook_plugged_cb would be called
by different threads.

Imaging the following calling sequence:
           Thread A                            Thread B
--------------------------------------------------------------------
mtk_hdmi_audio_hook_plugged_cb()
mtk_cec_hpd_high() -> disconnected
                                     hdmi_conn_detect()
                                     mtk_cec_hpd_high() -> connected
                                     plugged_cb(connected)
plugged_cb(disconnected)

The latest disconnected is false reported.  Makes mtk_cec_hpd_high
and plugged_cb atomic to fix.

Also uses the same lock to protect read/write of plugged_cb and codec_dev.

Fixes: 5d3c644773 ("drm/mediatek: support HDMI jack status reporting")
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Acked-by: CK Hu <ck.hu@mediatek.com>
Link: https://lore.kernel.org/r/20200217105513.2.I477092c2f104fd589133436c3ae4590e6fc6323b@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-02-17 17:39:13 +00:00
…
2020-01-18 09:19:18 -05:00
2020-02-09 16:08:48 -08:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
S
Description
No description provided
Readme
5.7 GiB
Languages
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%