[PATCH RESEND] tsl2550: fix lux1_input error in low light

From: Matt Ranostay
Date: Fri Dec 02 2016 - 15:37:10 EST


ADC channel 0 photodiode detects both infrared + visible light,
but ADC channel 1 just detects infrared. However, the latter is a bit
more sensitive in that range so complete darkness or low light causes
a error condition in which the chan0 - chan1 is negative that
results in a -EAGAIN.

This patch changes the resulting lux1_input sysfs attribute message from
"Resource temporarily unavailable" to a user-grokable lux value of 0.

Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Drew Fustini <pdp7pdp7@xxxxxxxxx>
Signed-off-by: Matt Ranostay <matt@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/tsl2550.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/tsl2550.c b/drivers/misc/tsl2550.c
index 87a13374fdc0..eb5761067310 100644
--- a/drivers/misc/tsl2550.c
+++ b/drivers/misc/tsl2550.c
@@ -177,7 +177,7 @@ static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
} else
lux = 0;
else
- return -EAGAIN;
+ return 0;

/* LUX range check */
return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux;
--
2.7.4