ALSA: Don't assume i2c device probing always succeeds
The client->driver pointer can be NULL when i2c-device probing fails
in i2c_new_device(). This patch adds the NULL checks for client->driver
and return the error instead of blind assumption of driver availability.
Reported-by: Tim Shepard <shep@alum.mit.edu>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/ppc/keywest.c b/sound/ppc/keywest.c
index 835fa19..bb6819a 100644
--- a/sound/ppc/keywest.c
+++ b/sound/ppc/keywest.c
@@ -59,6 +59,18 @@
strlcpy(info.type, "keywest", I2C_NAME_SIZE);
info.addr = keywest_ctx->addr;
keywest_ctx->client = i2c_new_device(adapter, &info);
+ if (!keywest_ctx->client)
+ return -ENODEV;
+ /*
+ * We know the driver is already loaded, so the device should be
+ * already bound. If not it means binding failed, and then there
+ * is no point in keeping the device instantiated.
+ */
+ if (!keywest_ctx->client->driver) {
+ i2c_unregister_device(keywest_ctx->client);
+ keywest_ctx->client = NULL;
+ return -ENODEV;
+ }
/*
* Let i2c-core delete that device on driver removal.