[PATCH v2 12/28] drm/i2c: tda998x: add DT support
From: Russell King - ARM Linux <hidden>
Date: 2014-01-11 18:03:21
Also in:
dri-devel, linux-devicetree, lkml
On Thu, Jan 09, 2014 at 12:03:24PM +0100, Jean-Francois Moine wrote:
This patch adds DT support to the tda998x. As a side effect, now, the audio sample rate is always 48kHz and the audio clock is always set. Signed-off-by: Jean-Francois Moine <redacted>
This patch breaks audio through the renaming of variable names. When you do such changes, *never* change all three together. Do them one at a time, replacing all instances of one variable before moving on to the next one. This avoids getting the names muddled up.
- struct tda998x_encoder_params params; + + u8 audio_type; /* audio type */ + u8 audio_frame[6]; + u32 audio_port;
"audio type" is a pointless comment for a variable called "audio_type". Explain what it is. It's the input format, which may be SPDIF or I2S.
/* Set audio input source */
- switch (p->audio_format) {
+ switch (priv->audio_type) {So, "audio_format" has become "audio_type" here.
quoted hunk ↗ jump to hunk
@@ -698,7 +703,13 @@ tda998x_encoder_set_config(struct drm_encoder *encoder, void *params) VIP_CNTRL_2_SWAP_F(p->swap_f) | (p->mirr_f ? VIP_CNTRL_2_MIRR_F : 0); - priv->params = *p; + memcpy(priv->audio_frame, p->audio_frame, + sizeof priv->audio_frame); + + if (p->audio_cfg) { + priv->audio_port = p->audio_cfg; + priv->audio_type = p->audio_format; + }
Here, audio_port and audio_type are only written to if audio_cfg is non-zero, which is not quite what is intended here. If you want DT to override this, then make that explicit. Moreover, we can see that this confirms that "audio_format" becomes "audio_type", and "audio_cfg" becomes "audio_port".
quoted hunk ↗ jump to hunk
@@ -947,8 +958,8 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder, tda998x_write_avi(priv, mode); - if (priv->params.audio_cfg) - tda998x_configure_audio(priv, mode, &priv->params); + if (priv->audio_type) + tda998x_configure_audio(priv, mode);
And here we have the real bug. "audio_cfg" has become "audio_type", which in the case of SPDIF, is zero. Hence, with a SPDIF source, tda998x_configure_audio() is no longer called. -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit".