enable HDMI audio output for HDMI monitors V2

Hello,

We can now enjoy music on HDMI monitors that are attached to Intel G35/G45 chipsets with the following X.org intel driver patches

[PATCH 1/3] introduce i830_hdmi_priv.has_hdmi_sink [PATCH 2/3] enable Intel G45 integrated HDMI audio output [PATCH 3/3] enable Intel G35 SDVO HDMI audio output

_and_ the corresponding ALSA patch posted at
http://mailman.alsa-project.org/pipermail/alsa-devel/2008-November/012158.html

The patches are tested OK on Intel DG45ID board, HP 2230s notebook and ASUS P5E-VM board.

Since the HDMI audio requires both audio and video driver support to function well, I'd like to provide an overview here.

1) driver components:
A) ALSA: audio driver (the above link)
B) Xorg: audio output enabling (this patchset)
C) Xorg: EDID/ELD information (patches to be submitted by Ma Ling)

2) summary of the feature sets:
- basic 2-channel audio:
(A) is required, (B) is mostly required, (C) is not needed
- 2+ multichannel audio:
not tested yet; in theory we need (C) to get HDMI monitor's speaker allocation configuration; there are also bandwidth constraints that should be coordinated between audio/video drivers in the future.
- non-LPCM audio:
not tested yet; need more work in ALSA code.

3) summary of the work flow:
- basic audio output: (A) and (B)
- ALSA HDMI driver: enable pin out and unmute
- ALSA HDMI driver: fill audio infoframe and enable its transmission
- Xorg intel driver: enable audio output
- ELD info for advanced audio capabilities: (A) and (C)
- Xorg xserver: get/parse/store EDID extensions
- Xorg xserver: transform EDID into ELD
- Xorg intel driver: feed ELD to hardware
- Xorg intel driver: set ELD-Valid flag to inform audio driver of new ELD
- ALSA HDMI driver: response to unsolicited response triggered by ELDV
- ALSA HDMI driver: get ELD from hardware
- ALSA HDMI driver: parse and show ELD info
- ALSA HDMI driver: update hardware capabilities/constraints according to ELD (TBD)

That describes my understandings of HDMI audio, comments and discussions are warmly welcome.

Thank you,
Fengguang
--

HDMI is compatible with DVI, and we've seen many boards that use HDMI port for DVI output.

So Zhenyu proposed this flag: i830_hdmi_priv.has_hdmi_sink to indicate the presence of HDMI capable monitors.

---
 src/i830_hdmi.c |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

@@ -38,6 +38,8 @@ struct i830_hdmi_priv {
     uint32_t output_reg;
 
     uint32_t save_SDVO;
+
+    Bool has_hdmi_sink;
 };
 
 static int

@@ -142,6 +144,8 @@ i830_hdmi_detect(xf86OutputPtr output)
     xf86OutputStatus status;
     xf86MonPtr edid_mon;
 
+    dev_priv->has_hdmi_sink = FALSE;
+
     /* For G4X desktop chip, PEG_BAND_GAP_DATA 3:0 must first be written 0xd.
      * Failure to do so will result in spurious interrupts being
      * generated on the port when a cable is not attached.

@@ -180,6 +184,16 @@ i830_hdmi_detect(xf86OutputPtr output)
     edid_mon = xf86OutputGetEDID (output, intel_output->pDDCBus);
     if (!edid_mon || !DIGITAL(edid_mon->features.input_type))
 	status = XF86OutputStatusDisconnected;
+
+    if (xf86MonitorIsHDMI(edid_mon))
+	dev_priv->has_hdmi_sink = TRUE;
+
+    if (pI830->debug_modes)
+	xf86DrvMsg(pScrn->scrnIndex, X_INFO,
+			"%s monitor detected on HDMI-%d\n",
+			dev_priv->has_hdmi_sink ? "HDMI" : "DVI",
+			(dev_priv->output_reg == SDVOB) ? 1 : 2);
+
     xfree(edid_mon);
     return status;
 }

@@ -232,6 +246,7 @@ i830_hdmi_init(ScrnInfoPtr pScrn, int ou
 
     dev_priv = (struct i830_hdmi_priv *)(intel_output + 1);
     dev_priv->output_reg = output_reg;
+    dev_priv->has_hdmi_sink = FALSE;
 
     intel_output->dev_priv = dev_priv;
     intel_output->type = I830_OUTPUT_HDMI;

Enable audio output for the integrated HDMI of Intel G45 chipset by introducing the SDVO_AUDIO_ENABLE bit.

---
 src/i810_reg.h  |    1 +
 src/i830_hdmi.c |    4 ++++
 2 files changed, 5 insertions(+)

@@ -1296,6 +1296,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN
 /** Requird for HDMI operation */
 #define SDVO_NULL_PACKETS_DURING_VSYNC		(1 << 9)
 #define SDVO_BORDER_ENABLE			(1 << 7)
+#define SDVO_AUDIO_ENABLE			(1 << 6)
 /** New with 965, default is to be set */
 #define SDVO_VSYNC_ACTIVE_HIGH			(1 << 4)
 /** New with 965, default is to be set */

@@ -80,6 +80,10 @@ i830_hdmi_mode_set(xf86OutputPtr output,
 	SDVO_BORDER_ENABLE |
 	SDVO_VSYNC_ACTIVE_HIGH |
 	SDVO_HSYNC_ACTIVE_HIGH;
+
+    if (dev_priv->has_hdmi_sink)
+	    sdvox |= SDVO_AUDIO_ENABLE;
+
     if (intel_crtc->pipe == 1)
 	sdvox |= SDVO_PIPE_B_SELECT;
 

From: Ma Ling <[email protected]>

Set the SDVO_AUDIO_ENABLE bit to enable SDVO HDMI audio output of the Intel G35 chipset.

---
 src/i830_sdvo.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

@@ -1019,7 +1019,7 @@ i830_sdvo_mode_set(xf86OutputPtr output,
     struct i830_sdvo_priv   *dev_priv = intel_output->dev_priv;
     xf86CrtcPtr	    crtc = output->crtc;
     I830CrtcPrivatePtr	    intel_crtc = crtc->driver_private;
-    uint32_t sdvox;
+    uint32_t sdvox = 0;
     int sdvo_pixel_multiply;
     struct i830_sdvo_in_out_map in_out;
     struct i830_sdvo_dtd input_dtd;

@@ -1041,8 +1041,10 @@ i830_sdvo_mode_set(xf86OutputPtr output,
 			&in_out, sizeof(in_out));
     status = i830_sdvo_read_response(output, NULL, 0);
 
-    if (dev_priv->is_hdmi)
+    if (dev_priv->is_hdmi) {
 	i830_sdvo_set_avi_infoframe(output, mode);
+	sdvox |= SDVO_AUDIO_ENABLE;
+    }
 
     i830_sdvo_get_dtd_from_mode(&input_dtd, mode);
 

@@ -1090,11 +1092,11 @@ i830_sdvo_mode_set(xf86OutputPtr output,
 
     /* Set the SDVO control regs. */
     if (IS_I965G(pI830)) {
-	sdvox = SDVO_BORDER_ENABLE |
+	sdvox |= SDVO_BORDER_ENABLE |
 		SDVO_VSYNC_ACTIVE_HIGH |
 		SDVO_HSYNC_ACTIVE_HIGH;
     } else {
-	sdvox = INREG(dev_priv->output_device);
+	sdvox |= INREG(dev_priv->output_device);
 	switch (dev_priv->output_device) {
 	case SDVOB:
 	    sdvox &= SDVOB_PRESERVE_MASK;

Patch series looks good to me.

- ajax

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Pushed xf86-video-intel patches. Thanks!

If you have HDMI output with intel graphics chips, you can test this now.

- alsa patch is within above mail, or get it from
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6.git

- after loading snd_hda_intel, 'aplay -l' should give you a list of devices that contains Intel HDMI device. Use that device for PCM. Current supports G35/G45/GM45.

- build xf86-video-intel git master to enable HDMI audio within video driver.

Open Source Technology Center, Intel ltd.

$gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827

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