Commit eeca59a6 authored by Alexander Tsoy's avatar Alexander Tsoy Committed by Takashi Iwai
Browse files

ALSA: usb-audio: Support read-only clock selector control 



Clock selector control might be read-only. Add corresponding checks
to prevent sending control requests that would fail.

Signed-off-by: default avatarAlexander Tsoy <alexander@tsoy.me>
Link: https://lore.kernel.org/r/20240125205457.28258-1-alexander@tsoy.me


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 668abe6d

sound/usb/clock.c

+22 −1
Original line number Diff line number Diff line
@@ -261,6 +261,8 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip, 
	int ret, i, cur, err, pins, clock_id;

	const u8 *sources;

	int proto = fmt->protocol;

	bool readable, writeable;

	u32 bmControls;



	entity_id &= 0xff;
@@ -292,11 +294,27 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip, 
		sources = GET_VAL(selector, proto, baCSourceID);

		cur = 0;



		if (proto == UAC_VERSION_3)

			bmControls = le32_to_cpu(*(__le32 *)(&selector->v3.baCSourceID[0] + pins));

		else

			bmControls = *(__u8 *)(&selector->v2.baCSourceID[0] + pins);



		readable = uac_v2v3_control_is_readable(bmControls,

							UAC2_CX_CLOCK_SELECTOR);

		writeable = uac_v2v3_control_is_writeable(bmControls,

							  UAC2_CX_CLOCK_SELECTOR);



		if (pins == 1) {

			ret = 1;

			goto find_source;

		}



		/* for now just warn about buggy device */

		if (!readable)

			usb_audio_warn(chip,

				"%s(): clock selector control is not readable, id %d\n",

				__func__, clock_id);



		/* the entity ID we are looking at is a selector.

		 * find out what it currently selects */

		ret = uac_clock_selector_get_val(chip, clock_id);
@@ -326,7 +344,7 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip, 
		if (ret > 0) {

			/* Skip setting clock selector again for some devices */

			if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR ||

			    pins == 1)

			    pins == 1 || !writeable)

				return ret;

			err = uac_clock_selector_set_val(chip, entity_id, cur);

			if (err < 0)
@@ -337,6 +355,9 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip, 
			return ret;



	find_others:

		if (!writeable)

			return -ENXIO;



		/* The current clock source is invalid, try others. */

		for (i = 1; i <= pins; i++) {

			if (i == cur)