(starting a new thread with the hope of being more precise after a lot of testing and rebooting)
I'm seeing a realtime patch related hard hang in the kernel alsa subsystem (MIDI input/output). In a nutshell:
- alsa rawmidi works (ie: "rawmidi -v -i hw:0" outputs a stream of messages when pointed to a midi capable card that has an external keyboard connected).
- the alsa sequencer interface works (ie: aplaymidi connected to aseqdump transfers data just fine).
- BOTH combined do NOT work (ie: use aconnect to connect the port that corresponds to the external midi interface to aseqdump: aseqdump hangs forever after transferring the first message and the only way out is a reboot).
Just tested this on 2.6.26.7 + rt11, Gina3G soundcard with an external MIDI keyboard sending messages. This is not specific to the Gina card, I have tested also USB midi interfaces and an RME hdsp card with a Multiface interface.
2.6.24.7 + rt21 works fine on the same hardware combinations. The standard Fedora 9 2.6.26.x kernel works fine as well.
I'm attaching the kernel configuration for the kernel I'm currently testing plus a dmesg dump of the whole boot process (rt kernel hackers can find there some additional sleeping in wrong context warning messages there), including the output of a "echo t >/proc/sysrq-trigger" that should show where aseqdump currently hangs (or so I think).
Hopefully this will narrow the area affected enough so that a solution can be found or more debugging info can be requested. Currently 2.6.26.x-rtx is unusable for musical purposes (at least when you have to interact with external midi controllers).
Thanks for any help... -- Fernando