From: Tanu Kaskinen Date: Thu, 5 Mar 2015 12:51:58 +0000 (+0200) Subject: ucm: improve jack configuration documentation X-Git-Tag: v1.1.0~84 X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=ecb38d2bec72a9fbb171e2e89816301d3451c8d3;p=alsa-lib.git ucm: improve jack configuration documentation Signed-off-by: Tanu Kaskinen Signed-off-by: Takashi Iwai --- diff --git a/include/use-case.h b/include/use-case.h index d3095224..e3308b17 100644 --- a/include/use-case.h +++ b/include/use-case.h @@ -301,12 +301,24 @@ int snd_use_case_get_list(snd_use_case_mgr_t *uc_mgr, * - name of capture mixer * - CaptureMixerID * - mixer capture ID - * - JackDev - * - jack device name - * - JackControl - * - jack control name - * - JackHWMute - * - indicate if the HW mutes a device on jack insertion or not. + * - JackControl, JackDev, JackHWMute + * - Jack information for a device. The jack status can be reported via + * a kcontrol and/or via an input device. **JackControl** is the + * kcontrol name of the jack, and **JackDev** is the input device id of + * the jack (if the full input device path is /dev/input/by-id/foo, the + * JackDev value should be "foo"). UCM configuration files should + * contain both JackControl and JackDev when possible, because + * applications are likely to support only one or the other. + * + * If **JackHWMute** is set, it indicates that when the jack is plugged + * in, the hardware automatically mutes some other device. The + * JackHWMute value is the name of the muted device. Note that + * JackHWMute should be used only when the hardware enforces the + * automatic muting. If the hardware doesn't enforce any muting, it may + * still be tempting to set JackHWMute to trick upper software layers to + * e.g. automatically mute speakers when headphones are plugged in, but + * that's application policy configuration that doesn't belong to UCM + * configuration files. */ int snd_use_case_get(snd_use_case_mgr_t *uc_mgr, const char *identifier,