2.4.6-ac2: "uart401: bad devc"

Linux 2.4.6-ac2 with CONFIG_MIDI_VIA82CXXX set does cause a kernel hang on my setup. On the first sound I play (ie cat >/dev/dsp) an endless stream of "uart401: bad devc" messages shows up on the console - everything else hangs.

Related config details:

/dev/dsp is on a sound blaster live, via82cxxx_audio is the second sound card (not really used). Both are loaded as modules.

emu10k1 and via82cxxx share the same interrupt (5). I assume that the via midi driver gets confused by the interrupt that was meant for the sound blaster live.

If I try a kernel without CONFIG_MIDI_VIA82CXXX defined, the problem disappears.

Jan

The attached patch should fix the problem.

Adrian Cox   http://www.humboldt.co.uk/

===== drivers/sound/via82cxxx_audio.c 1.12 vs edited =====

@@ -1641,7 +1641,8 @@
 	if (!(status32 & VIA_INTR_MASK))
         {
 #ifdef CONFIG_MIDI_VIA82CXXX
-                uart401intr(irq, card->midi_devc, regs);
+	    	 if (card->midi_devc)
+                    	uart401intr(irq, card->midi_devc, regs);
 #endif
 		return;
     	}