[PATCH v2] drm: dw-hdmi-i2s: enable audio clock in audio_startup

From: Cheng-Yi Chiang
Date: Sun Sep 01 2019 - 23:54:51 EST

In the designware databook, the sequence of enabling audio clock and
setting format is not clearly specified.
Currently, audio clock is enabled in the end of hw_param ops after
setting format.

On some monitors, there is a possibility that audio does not come out.
Fix this by enabling audio clock in audio_startup ops
before hw_param ops setting format.

Signed-off-by: Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Jonas Karlman <jonas@xxxxxxxxx>
Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Changes from v1:
1. Move audio_startup to the front of audio_shutdown.
2. Fix the indentation of audio_startup equal sign using tab.
3. Rebase the patch on linux-next/master.
4. Add Reviewed-by and Tested-by fields from dianders@xxxxxxxxxxxxx
5. Add Reviewed-by field from jonas@xxxxxxxxxx

drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c | 9 +++++++++
1 file changed, 9 insertions(+)

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 1d15cf9b6821..34d8e837555f 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-i2s-audio.c
@@ -109,6 +109,14 @@ static int dw_hdmi_i2s_hw_params(struct device *dev, void *data,
hdmi_write(audio, conf0, HDMI_AUD_CONF0);
hdmi_write(audio, conf1, HDMI_AUD_CONF1);

+ return 0;
+static int dw_hdmi_i2s_audio_startup(struct device *dev, void *data)
+ struct dw_hdmi_i2s_audio_data *audio = data;
+ struct dw_hdmi *hdmi = audio->hdmi;

return 0;
@@ -153,6 +161,7 @@ static int dw_hdmi_i2s_get_dai_id(struct snd_soc_component *component,

static struct hdmi_codec_ops dw_hdmi_i2s_ops = {
.hw_params = dw_hdmi_i2s_hw_params,
+ .audio_startup = dw_hdmi_i2s_audio_startup,
.audio_shutdown = dw_hdmi_i2s_audio_shutdown,
.get_eld = dw_hdmi_i2s_get_eld,
.get_dai_id = dw_hdmi_i2s_get_dai_id,