From: Surendra Singh Chouhan <kr494167@gmail.com>
p1_rtc_read_time() called if (!regmap_test_bits(regmap, RTC_CTRL, RTC_EN))
to check if the RTC was enabled.
regmap_test_bits() returns 1 if the bit is set, 0 if not set, and a
negative error code (e.g. -EIO) if reading the control register fails.
Using !regmap_test_bits(...) evaluates a negative error code as boolean
false, causing I2C/regmap read failures to be ignored and incorrectly
proceeding to read time registers from a failing device.
Fix this by capturing the return value of regmap_test_bits() and returning
the error code if negative, or -EINVAL if the RTC is disabled.
Fixes: a6de182daa2b ("rtc: spacemit: support the SpacemiT P1 RTC")
Signed-off-by: Surendra Singh Chouhan <kr494167@gmail.com>
---
drivers/rtc/rtc-spacemit-p1.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/rtc/rtc-spacemit-p1.c b/drivers/rtc/rtc-spacemit-p1.c
index 43ab62494bb4..c1820c920ba3 100644
--- a/drivers/rtc/rtc-spacemit-p1.c
+++ b/drivers/rtc/rtc-spacemit-p1.c
@@ -57,8 +57,9 @@ static int p1_rtc_read_time(struct device *dev, struct rtc_time *t)
u8 time[6];
int ret;
- if (!regmap_test_bits(regmap, RTC_CTRL, RTC_EN))
- return -EINVAL; /* RTC is disabled */
+ ret = regmap_test_bits(regmap, RTC_CTRL, RTC_EN);
+ if (ret <= 0)
+ return ret ? ret : -EINVAL; /* RTC is disabled or error */
ret = regmap_bulk_read(regmap, RTC_TIME, time, sizeof(time));
if (ret)
--
2.55.0