Re: [PATCH 01/11] drm: bridge/dw_hdmi: add audio sample channel status setting

On Fri, Jan 30, 2015 at 06:19:46AM -0500, Yakir Yang wrote:

When transmitting IEC60985 linear PCM audio, we configure the Aduio Sample Channel Status information of all the channel status bits in the IEC60958 frame.

It appears that the iMX6 version of the DW-HDMI IP does not have these registers. These registers are quite possibly only available on IPs which do not have the built-in AHB DMA, since the channel status bits are encoded into the samples in memory.

Can you report what identifying information your version of this IP outputs please? On iMX6, I get:

dwhdmi-imx 120000.hdmi: Detected HDMI controller 0x13:0xa:0xa0:0xc1

for iMX6Quad, and for iMX6Solo:

dwhdmi-imx 120000.hdmi: Detected HDMI controller 0x13:0x1a:0xa0:0xc1

Thanks.

Further comments below.

diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index 423addc..2ded957 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -204,6 +204,47 @@ static void hdmi_regenerate_n_cts(struct dw_hdmi *hdmi, unsigned int n, hdmi_writeb(hdmi, n & 0xff, HDMI_AUD_N1); }

+static void hdmi_set_schnl(struct dw_hdmi *hdmi) +{

• u8 aud_schnl_samplerate;
• switch (hdmi->sample_rate) {
• case 32000:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_32K;
  

• break;
  

• case 44100:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_44K1;
  

• break;
  

• case 48000:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_48K;
  

• break;
  

• case 88200:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_88K2;
  

• break;
  

• case 96000:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_96K;
  

• break;
  

• case 176400:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_176K4;
  

• break;
  

• case 192000:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_192K;
  

• break;
  

• case 768000:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_768K;
  

• break;
  

• default:

• aud_schnl_samplerate = HDMI_FC_AUDSCHNLS7_SMPRATE_44K1;
  

• break;
  

• }
• /* set channel status register */
• hdmi_modb(hdmi, aud_schnl_samplerate,

•   HDMI_FC_AUDSCHNLS7_SMPRATE_MASK, HDMI_FC_AUDSCHNLS7);
  

• hdmi_writeb(hdmi, ((~aud_schnl_samplerate) << 4) | 0x2,

•     HDMI_FC_AUDSCHNLS8);
  

+}

You should not split patches up like this - this patch introduces a new static function, which is never used until a subsequent patch. If this patch were to be merged, it would introduce a new build warning.

Please ensure that each patch in the series can be applied in sequence without causing a regression.

Thanks.