From 86c68e2fb3eeb87ef716a0d61c5a346e9aee2ecb Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 23 Nov 2015 14:44:13 +0100 Subject: [PATCH] backlight: adp88x0: Fix uninitialized variable use gcc correctly warns about both the adp8860 and adp8870 backlight drivers using an uninitialized variable in their error handling path: drivers/video/backlight/adp8870_bl.c: In function 'adp8870_bl_ambient_light_zone_store': drivers/video/backlight/adp8870_bl.c:811:11: warning: 'reg_val' may be used uninitialized in this function This changes the code to only write back the data if it was correctly read to start with. As a side-note, the drivers are mostly identical, so I think they should really be merged into one file to avoid having to fix every bug twice. Signed-off-by: Arnd Bergmann Acked-by: Michael Hennerich Signed-off-by: Lee Jones --- drivers/video/backlight/adp8860_bl.c | 10 ++++++---- drivers/video/backlight/adp8870_bl.c | 10 ++++++---- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/video/backlight/adp8860_bl.c b/drivers/video/backlight/adp8860_bl.c index 98ffe71e8af2..f0d4c0324580 100644 --- a/drivers/video/backlight/adp8860_bl.c +++ b/drivers/video/backlight/adp8860_bl.c @@ -621,10 +621,12 @@ static ssize_t adp8860_bl_ambient_light_zone_store(struct device *dev, /* Set user supplied ambient light zone */ mutex_lock(&data->lock); - adp8860_read(data->client, ADP8860_CFGR, ®_val); - reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT); - reg_val |= (val - 1) << CFGR_BLV_SHIFT; - adp8860_write(data->client, ADP8860_CFGR, reg_val); + ret = adp8860_read(data->client, ADP8860_CFGR, ®_val); + if (!ret) { + reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT); + reg_val |= (val - 1) << CFGR_BLV_SHIFT; + adp8860_write(data->client, ADP8860_CFGR, reg_val); + } mutex_unlock(&data->lock); } diff --git a/drivers/video/backlight/adp8870_bl.c b/drivers/video/backlight/adp8870_bl.c index 9d738352d7d4..21acac90fd77 100644 --- a/drivers/video/backlight/adp8870_bl.c +++ b/drivers/video/backlight/adp8870_bl.c @@ -807,10 +807,12 @@ static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev, /* Set user supplied ambient light zone */ mutex_lock(&data->lock); - adp8870_read(data->client, ADP8870_CFGR, ®_val); - reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT); - reg_val |= (val - 1) << CFGR_BLV_SHIFT; - adp8870_write(data->client, ADP8870_CFGR, reg_val); + ret = adp8870_read(data->client, ADP8870_CFGR, ®_val); + 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); } -- 2.20.1