On 11/14/19 4:27 PM, Takashi Iwai wrote:
> On Thu, 14 Nov 2019 04:37:02 +0100,
> Nikhil Mahale wrote:
>>
>> Document change notification HDA040-A for the Intel High Definition
>> Audio 1.0a specification introduces a Device Select verb for Digital
>> Display Pin Widgets that are multi-stream capable. This verb selects
>> a Device Entry that is used by subsequent Pin Widget verbs,
>> including the Get Connection List Entry verb.
>>
>> This patch queries the current Device Select value, associates it
>> with the connection list, and updates the connection list management
>> code to consider dev_id along with nid.
>
> I don't get why this is needed. This is the list that is added only
> from snd_hda_override_conn_list(), and you don't change that call
> pattern, so dev_id is always zero.
In follow-on patch "ALSA: hda - Add DP-MST support for non-acomp codecs",
hdmi_read_pin_conn() calls into snd_hda_set_dev_select() before
running into code path -
snd_hda_get_connections()
|-> snd_hda_get_conn_list()
|-> read_and_add_raw_conns()
|-> snd_hda_override_conn_list()
|-> add_conn_list()
If I understand spec correctly, conn_list need to read/write/track
along with device entry set into AC_VERB_SET_DEVICE_SEL verb, right?
This patch address that limited part here.
Thanks,
Nikhil Mahale
> thanks,
>
> Takashi
>
>>
>> Signed-off-by: Nikhil Mahale <nmahale@xxxxxxxxxx>
>> Reviewed-by: Aaron Plattner <aplattner@xxxxxxxxxx>
>> ---
>> sound/pci/hda/hda_codec.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
>> index a2fb19129219..8f32cab8f4a4 100644
>> --- a/sound/pci/hda/hda_codec.c
>> +++ b/sound/pci/hda/hda_codec.c
>> @@ -88,6 +88,7 @@ struct hda_conn_list {
>> struct list_head list;
>> int len;
>> hda_nid_t nid;
>> + int dev_id;
>> hda_nid_t conns[0];
>> };
>>
>> @@ -96,8 +97,9 @@ static struct hda_conn_list *
>> lookup_conn_list(struct hda_codec *codec, hda_nid_t nid)
>> {
>> struct hda_conn_list *p;
>> + int dev_id = snd_hda_get_dev_select(codec, nid);
>> list_for_each_entry(p, &codec->conn_list, list) {
>> - if (p->nid == nid)
>> + if (p->nid == nid && p->dev_id == dev_id)
>> return p;
>> }
>> return NULL;
>> @@ -113,6 +115,7 @@ static int add_conn_list(struct hda_codec *codec, hda_nid_t nid, int len,
>> return -ENOMEM;
>> p->len = len;
>> p->nid = nid;
>> + p->dev_id = snd_hda_get_dev_select(codec, nid);
>> memcpy(p->conns, list, len * sizeof(hda_nid_t));
>> list_add(&p->list, &codec->conn_list);
>> return 0;
>> --
>> 2.16.4
>>
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
