Make sure driver is attached before allocating a channel. Fixes a crash on

M2 Macbook Air with a newer device tree where aplaudio tries to allocate a
channel after apldma_attach() failed.

ok kettenis@

diff --git a/sys/arch/arm64/dev/apldma.c b/sys/arch/arm64/dev/apldma.c
index 8390003..cf6107f 100644 (file)
--- a/sys/arch/arm64/dev/apldma.c
+++ b/sys/arch/arm64/dev/apldma.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: apldma.c,v 1.3 2022/10/12 11:29:53 jsg Exp $  */
+/*     $OpenBSD: apldma.c,v 1.4 2022/10/23 22:15:45 tobhe Exp $        */
 /*
  * Copyright (c) 2022 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -259,7 +259,7 @@ apldma_alloc_channel(unsigned int chan)
        struct apldma_softc *sc = apldma_sc;
        struct apldma_channel *ac;
 
-       if (chan >= sc->sc_nchannels)
+       if (sc == NULL || chan >= sc->sc_nchannels)
                return NULL;
 
        /* We only support Tx channels for now. */