From: Roy Vegard Ovesen roy.vegard.ovesen@gmail.com
[ Upstream commit 659169c4eb21f8d9646044a4f4e1bc314f6f9d0c ]
The 1824c does not have the A/B switch that the 1810c has, but instead it has a mono main switch that sums the two main output channels to mono.
Signed-off-by: Roy Vegard Ovesen roy.vegard.ovesen@gmail.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org ---
LLM Generated explanations, may be completely bogus:
YES - Adds device-specific control IDs and state slots for the 1824c mono button so the driver can address the hardware selector correctly (`sound/usb/mixer_s1810c.c:94` and `sound/usb/mixer_s1810c.c:124`). - Introduces a dedicated `Mono Main Out` control wired into the existing switch helpers, replacing the bogus A/B selector previously shown to 1824c users and restoring the intended functionality (`sound/usb/mixer_s1810c.c:542`). - Updates mixer initialisation to choose the mono switch only for USB ID `0x194f:0x010d`, leaving the 1810c path unchanged, which confines the behaviour change to the affected device and avoids regressions on others (`sound/usb/mixer_s1810c.c:637`). - This is a hardware capability fix rather than a feature: without it, 1824c owners see an unusable control and cannot toggle the mono summing from ALSA, so backporting improves correctness with minimal code churn or architectural impact.
Suggested next step: verify on an 1824c that `alsamixer` now exposes a working mono main switch.
sound/usb/mixer_s1810c.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/sound/usb/mixer_s1810c.c b/sound/usb/mixer_s1810c.c index fac4bbc6b2757..bd24556f6a7fb 100644 --- a/sound/usb/mixer_s1810c.c +++ b/sound/usb/mixer_s1810c.c @@ -93,6 +93,7 @@ struct s1810c_ctl_packet {
#define SC1810C_CTL_LINE_SW 0 #define SC1810C_CTL_MUTE_SW 1 +#define SC1824C_CTL_MONO_SW 2 #define SC1810C_CTL_AB_SW 3 #define SC1810C_CTL_48V_SW 4
@@ -123,6 +124,7 @@ struct s1810c_state_packet { #define SC1810C_STATE_48V_SW 58 #define SC1810C_STATE_LINE_SW 59 #define SC1810C_STATE_MUTE_SW 60 +#define SC1824C_STATE_MONO_SW 61 #define SC1810C_STATE_AB_SW 62
struct s1810_mixer_state { @@ -502,6 +504,15 @@ static const struct snd_kcontrol_new snd_s1810c_mute_sw = { .private_value = (SC1810C_STATE_MUTE_SW | SC1810C_CTL_MUTE_SW << 8) };
+static const struct snd_kcontrol_new snd_s1824c_mono_sw = { + .iface = SNDRV_CTL_ELEM_IFACE_MIXER, + .name = "Mono Main Out Switch", + .info = snd_ctl_boolean_mono_info, + .get = snd_s1810c_switch_get, + .put = snd_s1810c_switch_set, + .private_value = (SC1824C_STATE_MONO_SW | SC1824C_CTL_MONO_SW << 8) +}; + static const struct snd_kcontrol_new snd_s1810c_48v_sw = { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = "48V Phantom Power On Mic Inputs Switch", @@ -588,8 +599,17 @@ int snd_sc1810_init_mixer(struct usb_mixer_interface *mixer) if (ret < 0) return ret;
- ret = snd_s1810c_switch_init(mixer, &snd_s1810c_ab_sw); - if (ret < 0) - return ret; + // The 1824c has a Mono Main switch instead of a + // A/B select switch. + if (mixer->chip->usb_id == USB_ID(0x194f, 0x010d)) { + ret = snd_s1810c_switch_init(mixer, &snd_s1824c_mono_sw); + if (ret < 0) + return ret; + } else if (mixer->chip->usb_id == USB_ID(0x194f, 0x010c)) { + ret = snd_s1810c_switch_init(mixer, &snd_s1810c_ab_sw); + if (ret < 0) + return ret; + } + return ret; }