[alsa-devel] [PATCH v2 2/3] drm/mediatek: support HDMI jack status reporting

[Tzung-Bi Shih]

On Thu, Feb 13, 2020 at 9:57 AM CK Hu <ck.hu at mediatek.com> wrote:
> I'm not only consider the race condition of plugged_cb and codec_dev. I
> also care about the atomic of mtk_cec_hpd_high() and hdmi->plugged_cb().
> If these two function is not an atomic operation, below is an example of
> problem:
>
> <Status disconnected>
> 1. Thread A call mtk_hdmi_audio_hook_plugged_cb()
> 2. Thread A call mtk_cec_hpd_high() and get disconnected.
> <Status connected>
> 3. Thread B call hdmi_conn_detect()
> 4. Thread B call mtk_cec_hpd_high() and get connected
> 5. Thread B callback plugged_cb() with connected
> 6. Thread A callback plugged_cb() with disconnected (Bug here)

Another attempt: https://patchwork.kernel.org/patch/11379979/