[alsa-devel] [RFC PATCH] ALSA : hda - not use assigned converters for all unused pins

[David Henningsson]

On 09/20/2013 10:00 AM, Lin, Mengdong wrote:
> Hi David,
> 
> Sorry, I missed your mail. Please see comments below ...
> 
>> -----Original Message-----
>> From: David Henningsson [mailto:david.henningsson at canonical.com]
>> Sent: Tuesday, September 17, 2013 6:40 AM
> 
>>> diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
>>> index 3d8cd044..4960695 100644
>>> --- a/sound/pci/hda/patch_hdmi.c
>>> +++ b/sound/pci/hda/patch_hdmi.c
>>> @@ -1152,29 +1152,34 @@ static void haswell_config_cvts(struct
>> hda_codec *codec,
>>>  			int pin_id, int mux_id)
>>>  {
>>>  	struct hdmi_spec *spec = codec->spec;
>>> -	struct hdmi_spec_per_pin *per_pin;
>>> -	int pin_idx, mux_idx;
>>> +	hda_nid_t  pin_nid;
>>> +	int pin_idx, cvt_idx;
>>>  	int curr;
>>> -	int err;
>>> -
>>> -	for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) {
>>> -		per_pin = get_pin(spec, pin_idx);
>>> +	struct hdmi_spec_per_cvt *per_cvt;
>>>
>>> +	/* configure all 3 pins, including "no physical connection" ones */
>>> +	for (pin_nid = 5; pin_nid < 8; pin_nid++) {
>>
>> It might not be so future proof to hard code nid IDs here (even if it should be
>> safe right now?). Perhaps more elegant to go through the entire codec->nids
>> array like being done here:
>>
>> http://lxr.linux.no/linux+*/sound/pci/hda/hda_auto_parser.c#L188
>>
>> The nid's wcaps is cached so it does not mean additional reads from the codec.
> 
> Xingchao defined haswell_config_cvts() to configure converters on codec->pins before.
> But codec->pins does not include the pins programmed by BIOS as "No physical connections" (like port B in the OEM machine).
> So I change the code from using codec->pins to hard coded NIDs. It's not graceful and the NIDs may change in the future.
> 
> There is another option to change add_pin() to not overlook such "no connection" pins for Haswell.

I was suggesting to do something like this in haswell_config_cvts:

	int end_nid = codec->start_nid + codec->num_nodes;
	for (nid = codec->start_nid; nid < end_nid; nid++) {
		unsigned int wid_caps = get_wcaps(codec, nid);
		if (get_wcaps_type(wid_caps) != AC_WID_PIN)
			continue;
                /* etc */


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic