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

Signed-off-by: Alexander Tsoy alexander@tsoy.me --- sound/usb/clock.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/sound/usb/clock.c b/sound/usb/clock.c index 94e4aaeafe58..7b259641adb5 100644 --- a/sound/usb/clock.c +++ b/sound/usb/clock.c @@ -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)