Merge tag 'v4.9-rc1' into x86/urgent, to pick up updates

Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 3cdf8e1ca0ad..051b14766ef9 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -593,6 +593,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	struct at24_data *at24;
 	int err;
 	unsigned i, num_addresses;
+	u8 test_byte;
 
 	if (client->dev.platform_data) {
 		chip = *(struct at24_platform_data *)client->dev.platform_data;
@@ -743,6 +744,18 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		}
 	}
 
+	i2c_set_clientdata(client, at24);
+
+	/*
+	 * Perform a one-byte test read to verify that the
+	 * chip is functional.
+	 */
+	err = at24_read(at24, 0, &test_byte, 1);
+	if (err) {
+		err = -ENODEV;
+		goto err_clients;
+	}
+
 	at24->nvmem_config.name = dev_name(&client->dev);
 	at24->nvmem_config.dev = &client->dev;
 	at24->nvmem_config.read_only = !writable;
@@ -764,8 +777,6 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		goto err_clients;
 	}
 
-	i2c_set_clientdata(client, at24);
-
 	dev_info(&client->dev, "%u byte %s EEPROM, %s, %u bytes/write\n",
 		chip.byte_len, client->name,
 		writable ? "writable" : "read-only", at24->write_max);