diff options
| author | Tzung-Bi Shih <tzungbi@google.com> | 2020-02-17 11:16:53 +0800 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-02-17 17:39:13 +0000 |
| commit | f07980d4ed60fbb35857b655c94b111f4ddf2abf (patch) | |
| tree | e347800766e82f56eff798f1e6951ba27d2bcea4 /drivers/gpu/drm/mediatek | |
| parent | 2f0b42034bd75a938cdf144149d6db4fa4d51208 (diff) | |
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: 5d3c64477392 ("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>
Diffstat (limited to 'drivers/gpu/drm/mediatek')
| -rw-r--r-- | drivers/gpu/drm/mediatek/mtk_hdmi.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c index 03aeb73005ef..d80017e3d84a 100644 --- a/drivers/gpu/drm/mediatek/mtk_hdmi.c +++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c @@ -12,6 +12,7 @@ #include <linux/io.h> #include <linux/kernel.h> #include <linux/mfd/syscon.h> +#include <linux/mutex.h> #include <linux/of_platform.h> #include <linux/of.h> #include <linux/of_gpio.h> @@ -171,6 +172,7 @@ struct mtk_hdmi { bool enabled; hdmi_codec_plugged_cb plugged_cb; struct device *codec_dev; + struct mutex update_plugged_status_lock; }; static inline struct mtk_hdmi *hdmi_ctx_from_bridge(struct drm_bridge *b) @@ -1199,10 +1201,13 @@ static void mtk_hdmi_clk_disable_audio(struct mtk_hdmi *hdmi) static enum drm_connector_status mtk_hdmi_update_plugged_status(struct mtk_hdmi *hdmi) { - bool connected = mtk_cec_hpd_high(hdmi->cec_dev); + bool connected; + mutex_lock(&hdmi->update_plugged_status_lock); + connected = mtk_cec_hpd_high(hdmi->cec_dev); if (hdmi->plugged_cb && hdmi->codec_dev) hdmi->plugged_cb(hdmi->codec_dev, connected); + mutex_unlock(&hdmi->update_plugged_status_lock); return connected ? connector_status_connected : connector_status_disconnected; @@ -1669,8 +1674,11 @@ static int mtk_hdmi_audio_hook_plugged_cb(struct device *dev, void *data, { struct mtk_hdmi *hdmi = data; + mutex_lock(&hdmi->update_plugged_status_lock); hdmi->plugged_cb = fn; hdmi->codec_dev = codec_dev; + mutex_unlock(&hdmi->update_plugged_status_lock); + mtk_hdmi_update_plugged_status(hdmi); return 0; @@ -1729,6 +1737,7 @@ static int mtk_drm_hdmi_probe(struct platform_device *pdev) return ret; } + mutex_init(&hdmi->update_plugged_status_lock); platform_set_drvdata(pdev, hdmi); ret = mtk_hdmi_output_init(hdmi); |