Re: [PATCH v4 2/2] ASoC: rt715:add micmute led state control supports

[Jaroslav Kysela]

Dne 22. 03. 21 v 10:25 Yuan, Perry napsal(a):
> Hi Mark:
> 
>> -----Original Message-----
>> From: Mark Brown <broonie@xxxxxxxxxx>
>> Sent: Tuesday, March 9, 2021 1:24 AM
>> To: Yuan, Perry
>> Cc: pobrn@xxxxxxxxxxxxxx; pierre-louis.bossart@xxxxxxxxxxxxxxx;
>> oder_chiou@xxxxxxxxxxx; perex@xxxxxxxx; tiwai@xxxxxxxx;
>> hdegoede@xxxxxxxxxx; mgross@xxxxxxxxxxxxxxx; Limonciello, Mario;
>> lgirdwood@xxxxxxxxx; alsa-devel@xxxxxxxxxxxxxxxx; linux-
>> kernel@xxxxxxxxxxxxxxx; platform-driver-x86@xxxxxxxxxxxxxxx
>> Subject: Re: [PATCH v4 2/2] ASoC: rt715:add micmute led state control
>> supports
>>
>> On Mon, Mar 01, 2021 at 05:38:34PM +0800, Perry Yuan wrote:
>>
>>> +	/* Micmute LED state changed by muted/unmute switch */
>>> +	if (mc->invert) {
>>> +		if (ucontrol->value.integer.value[0] || ucontrol-
>>> value.integer.value[1]) {
>>> +			micmute_led = LED_OFF;
>>> +		} else {
>>> +			micmute_led = LED_ON;
>>> +		}
>>> +		ledtrig_audio_set(LED_AUDIO_MICMUTE, micmute_led);
>>> +	}
>>
>> These conditionals on inversion seem weird and counterintuitive.  If we're
>> going with this approach it would probably be clearer to define a custom
>> operation for the affected controls that wraps the standard one and adds the
>> LED setting rather than keying off invert like this.
> 
> Currently the sof soundwire driver has no generic led control yet.
> This patch can handle the led control needs for MIC mute LED, definitely the patch is a short term solution.
> There is a feature request discussion when we started to implement this solution.
> https://github.com/thesofproject/linux/issues/2496#issuecomment-713892620
> 
> The workable way for now is that we put the LED mute control to the codec driver.
> When there is new and full sound LED solution implemented, this part will be also optimized.
> The Hardware privacy feature needs this patch to handle the Mic mute led state change.
> Before that full solution ready in kernel, could we take this as short term solution?

Perry, it's about the machine detection. Your code is too much generic even
for the top-level LED trigger implementation. We need an extra check, if the
proper LED's are really controlled on the specific hardware. Other hardware
may use RT715 for a different purpose. Use DMI / ACPI checks to detect this
hardware and don't misuse the inversion flag to enable this code.

						Jaroslav

-- 
Jaroslav Kysela <perex@xxxxxxxx>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.