IT WORKED! I fixed it in this way: mpu401_uart.c:229 if (mpu->hardware != MPU401_HW_TRID4DWAVE && mpu->hardware != MPU401_HW_ICE1712) { mpu->write(mpu, 0x00, MPU401D(mpu)); /*snd_mpu401_uart_clear_rx(mpu);*/ } I don't know if this will work on non-AMD machines and if it will work on all ice1712 machines... Next week I can test it with different M-Audio cards on single-processor machines (Pentium and AMD). Thanks a lot! Florian On 4/24/2007 5:04 PM, Takashi Iwai wrote: > At Tue, 24 Apr 2007 16:53:20 +0200, > Florian wrote: >>> When the hang-up occurs at the first write, it must be in >>> snd_mpu401_uart_cmd(). At the very beginning, it calls >>> mpu->write(mpu, 0x00, MPU401D(mpu)); Try to comment out this and >>> see what happens. >> I had tried that - I think that I just commented out the reset >> command. > > The reset command contains a series of writes. The write access (zero > to 0x304c) is the very first part, and this isn't always necessary. > For example, trident doesn't like this sequence. So, just commenting > out this write should be fairly harmless to the later behavior. > > So, commenting only the first zero write is worth to try (if you > didn't do yet). > > >> It would not crash or reboot, but it did not haver >> functionality either. > >>> Do I understand correctly that this bug happens when you open a >>> rawmidi device for read, e.g. % cat /dev/snd/midiC0D0 > /dev/null >>> >> yes. I usually used >> amidi -p hw:0 -d >> >>> Perhaps an easiest but foolishest way to trace this is to put >>> printk at each io-port access and any other important points, and >>> give some sleep at each point, then watch the kernel message. >>> You can get rid of spin_lock_*() around that, just for testing. >> I've done this until I traced it to the first outb() call, i.e. the >> initialization mentioned above. The first outb() will cause the reboot. > > And this causes an immediate reboot, not panic or oops, right? > You shouldn't do this kind of debug on X but on VGA console, BTW. > > > Takashi > > -- Florian Bomers bome.com ------------------------------------------------------- Music Software, Development Tools: http://www.bome.com Java Sound extensions, plugins: http://www.tritonus.org The Java Sound Resources: http://www.jsresources.org ------------------------------------------------------- Please quote this email in your reply. Thanks! _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel