[ 021/173] drivers/leds/leds-lp5521.c: fix lp5521_read() error handling

From: Ben Hutchings
Date: Fri Dec 28 2012 - 14:21:42 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 5bc9ad774c063f6b41965e7314f2c26aa5e465a0 upstream.

Gcc 4.6.2 complains that:

drivers/leds/leds-lp5521.c: In function `lp5521_load_program':
drivers/leds/leds-lp5521.c:214:21: warning: `mode' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c: In function `lp5521_probe':
drivers/leds/leds-lp5521.c:788:5: warning: `buf' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c:740:6: warning: `ret' may be used uninitialized in this function [-Wuninitialized]

These are real problems if lp5521_read() returns an error. When that
happens we should handle it, instead of ignoring it or doing a bitwise
OR with all the other error codes and continuing.

Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Milo <Milo.Kim@xxxxxx>
Cc: Richard Purdie <rpurdie@xxxxxxxxx>
Cc: Bryan Wu <bryan.wu@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/leds/leds-lp5521.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index 410a723..2381562 100644
--- a/drivers/leds/leds-lp5521.c
+++ b/drivers/leds/leds-lp5521.c
@@ -193,9 +193,14 @@ static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern)

/* move current engine to direct mode and remember the state */
ret = lp5521_set_engine_mode(eng, LP5521_CMD_DIRECT);
+ if (ret)
+ return ret;
+
/* Mode change requires min 500 us delay. 1 - 2 ms with margin */
usleep_range(1000, 2000);
- ret |= lp5521_read(client, LP5521_REG_OP_MODE, &mode);
+ ret = lp5521_read(client, LP5521_REG_OP_MODE, &mode);
+ if (ret)
+ return ret;

/* For loading, all the engines to load mode */
lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
@@ -211,8 +216,7 @@ static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern)
LP5521_PROG_MEM_SIZE,
pattern);

- ret |= lp5521_write(client, LP5521_REG_OP_MODE, mode);
- return ret;
+ return lp5521_write(client, LP5521_REG_OP_MODE, mode);
}

static int lp5521_set_led_current(struct lp5521_chip *chip, int led, u8 curr)
@@ -785,7 +789,7 @@ static int __devinit lp5521_probe(struct i2c_client *client,
* LP5521_REG_ENABLE register will not have any effect - strange!
*/
ret = lp5521_read(client, LP5521_REG_R_CURRENT, &buf);
- if (buf != LP5521_REG_R_CURR_DEFAULT) {
+ if (ret || buf != LP5521_REG_R_CURR_DEFAULT) {
dev_err(&client->dev, "error in resetting chip\n");
goto fail2;
}


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