Re: [alsa-devel] [PATCH v4 4/5] ALSA: hda - hdmi dynamically bind PCM to pin when monitor hotplug

On 12/16/2015 03:43 PM, Takashi Iwai wrote:

On Wed, 16 Dec 2015 06:42:44 +0100, libin.yang@linux.intel.com wrote:

...

From: Libin Yang libin.yang@linux.intel.com

Dynamically bind/unbind the PCM to pin when HDMI/DP monitor hotplug.

When monitor is connected, find a proper PCM for the monitor. When monitor is disconnected, unbind the PCM from the pin.

The binding policy (use Intel platform as example) is:

1. Try to use the legacy pin-pcm mapping for the device entry 0 of the pin.
2. If step 1 fails, try to bind pin to the backup PCMs. For example, on Intel platform, if DP MST is enabled, 5 PCMs will be created. PCM 3, PCM 7, PCM 8 are supposed to be used by device entry 0 of pin 5, pin 6 and pin 7. PCM 9 and PCM 10 are the backup PCMs.
3. If step 2 fails, try to find any PCM to bind to the pin.

Signed-off-by: Libin Yang libin.yang@linux.intel.com

This patch adds the code in sync_eld_via_acomp(), i.e. it's handled only with component. As the dynamic HDA attach/detach itself is agnostic to the component, I'd suggest to put this rather in update_eld().

Also pcm_lock can be put in hdmi_present_sense() to wrap both sync_eld_via_acomp() and hdmi_present_sense_via_verbs().

OK, I will put it in update_eld().

Best Regards, Libin

Takashi

...

---

sound/pci/hda/patch_hdmi.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+)

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c index 19bf782..10edab8 100644 --- a/sound/pci/hda/patch_hdmi.c +++ b/sound/pci/hda/patch_hdmi.c @@ -73,6 +73,8 @@ struct hdmi_spec_per_cvt {

struct hdmi_spec_per_pin { hda_nid_t pin_nid;

• /* pin idx, different device entries on the same pin use the same idx */
• int pin_nid_idx; int num_mux_nids; hda_nid_t mux_nids[HDA_MAX_CONNECTIONS]; int mux_idx;

@@ -85,6 +87,7 @@ struct hdmi_spec_per_pin { struct snd_kcontrol *eld_ctl; struct snd_jack *acomp_jack; /* jack via audio component */ struct hda_pcm *pcm; /* pointer to spec->pcm_rec[n] dynamically*/

• int pcm_idx; /* which pcm is attached. -1 means no pcm is attached */ int repoll_count; bool setup; /* the stream has been set up by prepare callback */ int channels; /* current number of channels */

@@ -138,6 +141,8 @@ struct hdmi_spec { struct snd_array pins; /* struct hdmi_spec_per_pin */ struct hda_pcm *pcm_rec[16]; struct mutex pcm_lock;

• /* pcm_bitmap means which pcms have been assigned to pins*/
• unsigned long pcm_bitmap; int pcm_used; /* counter of pcm_rec[] */ unsigned int channels_max; /* max over all cvts */

@@ -1786,6 +1791,60 @@ static bool hdmi_present_sense_via_verbs(struct hdmi_spec_per_pin *per_pin, return ret; }

+static int hdmi_find_pcm_slot(struct hdmi_spec *spec,

• 		struct hdmi_spec_per_pin *per_pin)
  

+{

• int i;
• /* try the prefer PCM */
• if (!test_bit(per_pin->pin_nid_idx, &spec->pcm_bitmap))

• return per_pin->pin_nid_idx;
  

• /* have a second try; check the "reserved area" over num_pins */
• for (i = spec->num_pins; i < spec->pcm_used; i++) {

• if (!test_bit(i, &spec->pcm_bitmap))
  

• 	return i;
  

• }
• /* the last try; check the empty slots in pins */
• for (i = 0; i < spec->num_pins; i++) {

• if (!test_bit(i, &spec->pcm_bitmap))
  

• 	return i;
  

• }
• return -EBUSY;

+}

+static void hdmi_attach_hda_pcm(struct hdmi_spec *spec,

• 		struct hdmi_spec_per_pin *per_pin)
  

+{

• int idx;
• /* pcm already be attached to the pin */
• if (per_pin->pcm)

• return;
  

• idx = hdmi_find_pcm_slot(spec, per_pin);
• if (idx == -ENODEV)

• return;
  

• per_pin->pcm_idx = idx;
• per_pin->pcm = spec->pcm_rec[idx];
• set_bit(idx, &spec->pcm_bitmap);

+}

+static void hdmi_detach_hda_pcm(struct hdmi_spec *spec,

• 		struct hdmi_spec_per_pin *per_pin)
  

+{

• int idx;
• /* pcm already be detached from the pin */
• if (!per_pin->pcm)

• return;
  

• idx = per_pin->pcm_idx;
• per_pin->pcm_idx = -1;
• per_pin->pcm = NULL;
• if (idx >= 0 && idx < spec->pcm_used)

• clear_bit(idx, &spec->pcm_bitmap);
  

+}

• /* update ELD and jack state via audio component */ static void sync_eld_via_acomp(struct hda_codec *codec, struct hdmi_spec_per_pin *per_pin)

@@ -1794,6 +1853,7 @@ static void sync_eld_via_acomp(struct hda_codec *codec, struct hdmi_eld *eld = &spec->temp_eld; int size;

• mutex_lock(&spec->pcm_lock); mutex_lock(&per_pin->lock); size = snd_hdac_acomp_get_eld(&codec->bus->core, per_pin->pin_nid, &eld->monitor_present, eld->eld_buffer,

@@ -1815,11 +1875,19 @@ static void sync_eld_via_acomp(struct hda_codec *codec, eld->eld_size = 0; }

• if (spec->dyn_pcm_assign) {

• if (eld->eld_valid)
  

• 	hdmi_attach_hda_pcm(spec, per_pin);
  

• else
  

• 	hdmi_detach_hda_pcm(spec, per_pin);
  

• }

• update_eld(codec, per_pin, eld); snd_jack_report(per_pin->acomp_jack, eld->monitor_present ? SND_JACK_AVOUT : 0); unlock: mutex_unlock(&per_pin->lock);

• mutex_unlock(&spec->pcm_lock); }

  static bool hdmi_present_sense(struct hdmi_spec_per_pin *per_pin, int repoll)

@@ -1875,6 +1943,11 @@ static int hdmi_add_pin(struct hda_codec *codec, hda_nid_t pin_nid)

per_pin->pin_nid = pin_nid; per_pin->non_pcm = false;

• if (spec->dyn_pcm_assign)

• per_pin->pcm_idx = -1;
  

• else

• per_pin->pcm_idx = pin_idx;
  

• per_pin->pin_nid_idx = pin_idx;

  err = hdmi_read_pin_conn(codec, pin_idx); if (err < 0)

-- 1.9.1