[PATCH 2/2] lp855x_bl: remove unnecessary mutex code

From: Kim, Milo
Date: Fri Oct 19 2012 - 04:12:05 EST


The mutex for accessing lp855x registers is used in case of
the user-space interaction.
When the brightness is changed via the sysfs, the mutex is required.
But the backlight class device already provides it.
Thus, the lp855x mutex is unnecessary.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@xxxxxx>
---
drivers/video/backlight/lp855x_bl.c | 14 +-------------
1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/drivers/video/backlight/lp855x_bl.c b/drivers/video/backlight/lp855x_bl.c
index c4fd72f..ff86531 100644
--- a/drivers/video/backlight/lp855x_bl.c
+++ b/drivers/video/backlight/lp855x_bl.c
@@ -35,7 +35,6 @@ struct lp855x {
struct i2c_client *client;
struct backlight_device *bl;
struct device *dev;
- struct mutex xfer_lock;
struct lp855x_platform_data *pdata;
struct pwm_device *pwm;
};
@@ -44,14 +43,11 @@ static int lp855x_read_byte(struct lp855x *lp, u8 reg, u8 *data)
{
int ret;

- mutex_lock(&lp->xfer_lock);
ret = i2c_smbus_read_byte_data(lp->client, reg);
if (ret < 0) {
- mutex_unlock(&lp->xfer_lock);
dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
return ret;
}
- mutex_unlock(&lp->xfer_lock);

*data = (u8)ret;
return 0;
@@ -59,13 +55,7 @@ static int lp855x_read_byte(struct lp855x *lp, u8 reg, u8 *data)

static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
{
- int ret;
-
- mutex_lock(&lp->xfer_lock);
- ret = i2c_smbus_write_byte_data(lp->client, reg, data);
- mutex_unlock(&lp->xfer_lock);
-
- return ret;
+ return i2c_smbus_write_byte_data(lp->client, reg, data);
}

static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
@@ -278,8 +268,6 @@ static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
lp->chip_id = id->driver_data;
i2c_set_clientdata(cl, lp);

- mutex_init(&lp->xfer_lock);
-
ret = lp855x_init_registers(lp);
if (ret) {
dev_err(lp->dev, "i2c communication err: %d", ret);
--
1.7.9.5


Best Regards,
Milo


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