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/aoa/codecs/tas.c b/sound/aoa/codecs/tas.c
index f0ebc97..1dd66dd 100644 (file)
--- a/sound/aoa/codecs/tas.c
+++ b/sound/aoa/codecs/tas.c
@@ -897,6 +897,15 @@ static int tas_create(struct i2c_adapter *adapter,
        client = i2c_new_device(adapter, &info);
        if (!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 (!client->driver) {
+               i2c_unregister_device(client);
+               return -ENODEV;
+       }
 
        /*
         * Let i2c-core delete that device on driver removal.

diff --git a/sound/ppc/keywest.c b/sound/ppc/keywest.c
index 835fa19..bb6819a 100644 (file)
--- a/sound/ppc/keywest.c
+++ b/sound/ppc/keywest.c
@@ -59,6 +59,18 @@ static int keywest_attach_adapter(struct i2c_adapter *adapter)
        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.