3.16.51-rc1 review patch. If anyone has any objections, please let me know.
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From: Bhushan Shah bshah@kde.org
commit 06168a64b1ae346816fcd0a0c3ea5276c778408b upstream.
In the lm3630a_chip_init we try to write to 0x50 register, which is higher value then the max_register value, this resulted in regmap_write return -EIO.
Fix this by bumping REG_MAX value to 0x50.
This code was introduced with the chip revision in commit 28e64a68a2ef, however setting filter strength was failing silently because it used unsigned int for storing and comparing the return values. Bug related to signedness was fixed in 2a0c316bf3cc, which made it error out correctly instead of failing silently.
I found this issue by using this driver on LGE Nexus 5 (hammerhead). After this commit lm3630a_chip_init succeeds instead of failing with -EIO.
Fixes: 28e64a68a2ef ("backlight: lm3630: apply chip revision") Fixes: 2a0c316bf3cc ("drivers/video/backlight/lm3630a_bl.c: fix signedness bug in lm3630a_chip_init()")
Suggested-by: Bjorn Andersson bjorn.andersson@linaro.org Signed-off-by: Bhushan Shah bshah@kde.org Acked-by: Daniel Thompson daniel.thompson@linaro.org Signed-off-by: Lee Jones lee.jones@linaro.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/video/backlight/lm3630a_bl.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/video/backlight/lm3630a_bl.c +++ b/drivers/video/backlight/lm3630a_bl.c @@ -31,7 +31,8 @@ #define REG_FAULT 0x0B #define REG_PWM_OUTLOW 0x12 #define REG_PWM_OUTHIGH 0x13 -#define REG_MAX 0x1F +#define REG_FILTER_STRENGTH 0x50 +#define REG_MAX 0x50
#define INT_DEBOUNCE_MSEC 10 struct lm3630a_chip { @@ -80,7 +81,7 @@ static int lm3630a_chip_init(struct lm36
usleep_range(1000, 2000); /* set Filter Strength Register */ - rval = lm3630a_write(pchip, 0x50, 0x03); + rval = lm3630a_write(pchip, REG_FILTER_STRENGTH, 0x03); /* set Cofig. register */ rval |= lm3630a_update(pchip, REG_CONFIG, 0x07, pdata->pwm_ctrl); /* set boost control */