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

From: Dan Carpenter
Date: Wed Feb 01 2012 - 09:40:43 EST

Gcc 4.6.2 complains that:
drivers/leds/leds-lp5521.c: In function âlp5521_load_programâ:
drivers/leds/leds-lp5521.c:214:21: warning: âmodeâ may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c: In function âlp5521_probeâ:
drivers/leds/leds-lp5521.c:788:5: warning: âbufâ may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c:740:6: warning: âretâ 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>

diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index de7b8fe..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)

- 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)
@@ -784,8 +788,8 @@ static int __devinit lp5521_probe(struct i2c_client *client,
* otherwise further access to the R G B channels in the
* LP5521_REG_ENABLE register will not have any effect - strange!
- lp5521_read(client, LP5521_REG_R_CURRENT, &buf);
- if (buf != LP5521_REG_R_CURR_DEFAULT) {
+ ret = lp5521_read(client, LP5521_REG_R_CURRENT, &buf);
+ if (ret || buf != LP5521_REG_R_CURR_DEFAULT) {
dev_err(&client->dev, "error in resetting chip\n");
goto fail2;
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