Re: [PATCH] backlight: (adp8870) fix a missing check for adp8870_write

On Tue, Dec 25, 2018 at 12:21:09AM -0600, Kangjie Lu wrote:

adp8870_write() may fail. This fix checks if adp8870_write fails, and if so, returns its error code.

Signed-off-by: Kangjie Lu kjlu@umn.edu

drivers/video/backlight/adp8870_bl.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/video/backlight/adp8870_bl.c b/drivers/video/backlight/adp8870_bl.c index 8d50e0299578..79901fb4fcd1 100644 --- a/drivers/video/backlight/adp8870_bl.c +++ b/drivers/video/backlight/adp8870_bl.c @@ -811,9 +811,14 @@ static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev, if (!ret) { reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT); reg_val |= (val - 1) << CFGR_BLV_SHIFT;

• 	adp8870_write(data->client, ADP8870_CFGR, reg_val);
  

• }
  

• mutex_unlock(&data->lock);
  

• 	ret = adp8870_write(data->client,
  

• 			ADP8870_CFGR, reg_val);
  

• 	if (ret) {
  

• 		mutex_unlock(&data->lock);
  

• 		return ret;
  

• 	}
  

• }	else
  

• 	mutex_unlock(&data->lock);
  

Please don't unbalance the lock paths. Instead check the value of ret *after* the existing mutex unlock (which will also means that the failed adp8870_read() isn't silently ignored).

Also there's not much point in fixing this site without also fixing the missing return checks on adp8870_set_bits() and adp8870_clr_bits() in the same function.

Daniel.

}

return count;

2.17.2 (Apple Git-113)