Re: [PATCH v3 2/5] drm: bridge: dw-hdmi: Report connector status using callback
On Fri, Jul 12, 2019 at 6:48 PM Russell King - ARM Linux admin wrote: > > On Fri, Jul 12, 2019 at 06:04:40PM +0800, Cheng-Yi Chiang wrote: > > Allow codec driver register callback function for plug event. > > > > The callback registration flow: > > dw-hdmi <--- hw-hdmi-i2s-audio <--- hdmi-codec > > > > dw-hdmi-i2s-audio implements hook_plugged_cb op > > so codec driver can register the callback. > > > > dw-hdmi implements set_plugged_cb op so platform device can register the > > callback. > > > > When connector plug/unplug event happens, report this event using the > > callback. > > > > Make sure that audio and drm are using the single source of truth for > > connector status. > > > > Signed-off-by: Cheng-Yi Chiang > > --- > > .../gpu/drm/bridge/synopsys/dw-hdmi-audio.h | 3 + > > .../drm/bridge/synopsys/dw-hdmi-i2s-audio.c | 10 > > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 55 ++- > > 3 files changed, 67 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > > index 63b5756f463b..f523c590984e 100644 > > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > > @@ -2,6 +2,8 @@ > > #ifndef DW_HDMI_AUDIO_H > > #define DW_HDMI_AUDIO_H > > > > +#include > > + > > struct dw_hdmi; > > > > struct dw_hdmi_audio_data { > > @@ -17,6 +19,7 @@ struct dw_hdmi_i2s_audio_data { > > > > void (*write)(struct dw_hdmi *hdmi, u8 val, int offset); > > u8 (*read)(struct dw_hdmi *hdmi, int offset); > > + int (*set_plugged_cb)(struct dw_hdmi *hdmi, hdmi_codec_plugged_cb fn); > > }; > > > > #endif > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > > index 5cbb71a866d5..7b93cf05c985 100644 > > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > > @@ -104,10 +104,20 @@ static int dw_hdmi_i2s_get_dai_id(struct > > snd_soc_component *component, > > return -EINVAL; > > } > > > > +static int dw_hdmi_i2s_hook_plugged_cb(struct device *dev, void *data, > > +hdmi_codec_plugged_cb fn) > > +{ > > + struct dw_hdmi_i2s_audio_data *audio = data; > > + struct dw_hdmi *hdmi = audio->hdmi; > > + > > + return audio->set_plugged_cb(hdmi, fn); > > +} > > + > > static struct hdmi_codec_ops dw_hdmi_i2s_ops = { > > .hw_params = dw_hdmi_i2s_hw_params, > > .audio_shutdown = dw_hdmi_i2s_audio_shutdown, > > .get_dai_id = dw_hdmi_i2s_get_dai_id, > > + .hook_plugged_cb = dw_hdmi_i2s_hook_plugged_cb, > > }; > > > > static int snd_dw_hdmi_probe(struct platform_device *pdev) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > > index 045b1b13fd0e..ce6646067472 100644 > > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > > @@ -26,6 +26,8 @@ > > #include > > #include > > > > +#include > > + > > #include > > #include > > > > @@ -185,6 +187,9 @@ struct dw_hdmi { > > void (*disable_audio)(struct dw_hdmi *hdmi); > > > > struct cec_notifier *cec_notifier; > > + > > + hdmi_codec_plugged_cb plugged_cb; > > + enum drm_connector_status last_connector_result; > > }; > > > > #define HDMI_IH_PHY_STAT0_RX_SENSE \ > > @@ -209,6 +214,40 @@ static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int > > offset) > > return val; > > } > > > > +static void handle_plugged_change(struct dw_hdmi *hdmi, bool plugged) > > +{ > > + struct platform_device *codec_pdev; > > + > > + if (!hdmi->audio || IS_ERR(hdmi->audio)) > > + return; > > + codec_pdev = platform_get_drvdata(hdmi->audio); > > + if (!codec_pdev || IS_ERR(codec_pdev)) > > + return; > > This looks fragile to me, poking about in another device's driver data > from another driver is really not a good design decision. I think this > can be simplified if the registration function took the function > pointer and the struct device pointer, and then you only need one test > below: > Hi Russell, Thank you for the detailed review. ACK to this suggestion. I have updated the registration function following your suggestion in v4. It looks much cleaner. > > + if (!hdmi->plugged_cb) > > + return; > > + > > + hdmi->plugged_cb(&codec_pdev->dev, plugged); > > +} > > + > > +static int hdmi_set_plugged_cb(struct dw_hdmi *hdmi, hdmi_codec_plugged_cb > > fn) > > +{ > > + bool plugged; > > + struct platform_device *codec_pdev; > > + > > + if (!hdmi->audio || IS_ERR(hdmi->audio)) > > + return -EINVAL; > > Given the current code structure, how can this ever be true when the > function is called? > ACK Removed in v4. > > + codec_pdev = platform_get_drvdata(hdmi->audio); > > +
Re: [PATCH v3 2/5] drm: bridge: dw-hdmi: Report connector status using callback
On Fri, Jul 12, 2019 at 06:04:40PM +0800, Cheng-Yi Chiang wrote: > Allow codec driver register callback function for plug event. > > The callback registration flow: > dw-hdmi <--- hw-hdmi-i2s-audio <--- hdmi-codec > > dw-hdmi-i2s-audio implements hook_plugged_cb op > so codec driver can register the callback. > > dw-hdmi implements set_plugged_cb op so platform device can register the > callback. > > When connector plug/unplug event happens, report this event using the > callback. > > Make sure that audio and drm are using the single source of truth for > connector status. > > Signed-off-by: Cheng-Yi Chiang > --- > .../gpu/drm/bridge/synopsys/dw-hdmi-audio.h | 3 + > .../drm/bridge/synopsys/dw-hdmi-i2s-audio.c | 10 > drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 55 ++- > 3 files changed, 67 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > index 63b5756f463b..f523c590984e 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-audio.h > @@ -2,6 +2,8 @@ > #ifndef DW_HDMI_AUDIO_H > #define DW_HDMI_AUDIO_H > > +#include > + > struct dw_hdmi; > > struct dw_hdmi_audio_data { > @@ -17,6 +19,7 @@ struct dw_hdmi_i2s_audio_data { > > void (*write)(struct dw_hdmi *hdmi, u8 val, int offset); > u8 (*read)(struct dw_hdmi *hdmi, int offset); > + int (*set_plugged_cb)(struct dw_hdmi *hdmi, hdmi_codec_plugged_cb fn); > }; > > #endif > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > index 5cbb71a866d5..7b93cf05c985 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c > @@ -104,10 +104,20 @@ static int dw_hdmi_i2s_get_dai_id(struct > snd_soc_component *component, > return -EINVAL; > } > > +static int dw_hdmi_i2s_hook_plugged_cb(struct device *dev, void *data, > +hdmi_codec_plugged_cb fn) > +{ > + struct dw_hdmi_i2s_audio_data *audio = data; > + struct dw_hdmi *hdmi = audio->hdmi; > + > + return audio->set_plugged_cb(hdmi, fn); > +} > + > static struct hdmi_codec_ops dw_hdmi_i2s_ops = { > .hw_params = dw_hdmi_i2s_hw_params, > .audio_shutdown = dw_hdmi_i2s_audio_shutdown, > .get_dai_id = dw_hdmi_i2s_get_dai_id, > + .hook_plugged_cb = dw_hdmi_i2s_hook_plugged_cb, > }; > > static int snd_dw_hdmi_probe(struct platform_device *pdev) > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > index 045b1b13fd0e..ce6646067472 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c > @@ -26,6 +26,8 @@ > #include > #include > > +#include > + > #include > #include > > @@ -185,6 +187,9 @@ struct dw_hdmi { > void (*disable_audio)(struct dw_hdmi *hdmi); > > struct cec_notifier *cec_notifier; > + > + hdmi_codec_plugged_cb plugged_cb; > + enum drm_connector_status last_connector_result; > }; > > #define HDMI_IH_PHY_STAT0_RX_SENSE \ > @@ -209,6 +214,40 @@ static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int > offset) > return val; > } > > +static void handle_plugged_change(struct dw_hdmi *hdmi, bool plugged) > +{ > + struct platform_device *codec_pdev; > + > + if (!hdmi->audio || IS_ERR(hdmi->audio)) > + return; > + codec_pdev = platform_get_drvdata(hdmi->audio); > + if (!codec_pdev || IS_ERR(codec_pdev)) > + return; This looks fragile to me, poking about in another device's driver data from another driver is really not a good design decision. I think this can be simplified if the registration function took the function pointer and the struct device pointer, and then you only need one test below: > + if (!hdmi->plugged_cb) > + return; > + > + hdmi->plugged_cb(&codec_pdev->dev, plugged); > +} > + > +static int hdmi_set_plugged_cb(struct dw_hdmi *hdmi, hdmi_codec_plugged_cb > fn) > +{ > + bool plugged; > + struct platform_device *codec_pdev; > + > + if (!hdmi->audio || IS_ERR(hdmi->audio)) > + return -EINVAL; Given the current code structure, how can this ever be true when the function is called? > + codec_pdev = platform_get_drvdata(hdmi->audio); > + if (!codec_pdev || IS_ERR(codec_pdev)) > + return -EINVAL; This doesn't seem like a good idea as I've pointed out above. > + > + mutex_lock(&hdmi->mutex); > + hdmi->plugged_cb = fn; > + plugged = hdmi->last_connector_result == connector_status_connected; > + handle_plugged_change(hdmi, plugged); > + mutex_unlock(&hdmi->mutex); Should be a blank line here for readability. > + return 0; > +} > + > static void hdmi_modb(struct dw_hdmi *hdmi, u8 data, u8 mask,