The ALSA id sysattr is generated by the sound subsystem and is not a stable identifier. It is generated though some string manipulation then made unique if there is a conflict. This means that it is enumeration-dependent and shouldn't be used for ID_ID.
If ID_ID is supposed to be system-unique, it is not already since for firewire it is generated from the guid and there are broken firewire devices that have duplicate guids across devices. This is tracked for PulseAudio at https://bugs.freedesktop.org/show_bug.cgi?id=90129. --- rules/78-sound-card.rules | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/rules/78-sound-card.rules b/rules/78-sound-card.rules index 295f490..bd7a994 100644 --- a/rules/78-sound-card.rules +++ b/rules/78-sound-card.rules @@ -49,8 +49,8 @@ SUBSYSTEMS=="firewire", GOTO="skip_pci" SUBSYSTEMS=="pci", ENV{ID_BUS}="pci", ENV{ID_VENDOR_ID}="$attr{vendor}", ENV{ID_MODEL_ID}="$attr{device}" LABEL="skip_pci" -ENV{ID_SERIAL}=="?*", ENV{ID_USB_INTERFACE_NUM}=="?*", ENV{ID_ID}="$env{ID_BUS}-$env{ID_SERIAL}-$env{ID_USB_INTERFACE_NUM}-$attr{id}" -ENV{ID_SERIAL}=="?*", ENV{ID_USB_INTERFACE_NUM}=="", ENV{ID_ID}="$env{ID_BUS}-$env{ID_SERIAL}-$attr{id}" +ENV{ID_SERIAL}=="?*", ENV{ID_USB_INTERFACE_NUM}=="?*", ENV{ID_ID}="$env{ID_BUS}-$env{ID_SERIAL}-$env{ID_USB_INTERFACE_NUM}" +ENV{ID_SERIAL}=="?*", ENV{ID_USB_INTERFACE_NUM}=="", ENV{ID_ID}="$env{ID_BUS}-$env{ID_SERIAL}" IMPORT{builtin}="path_id" -- 2.2.0.rc0.207.ga3a616c _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel