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rtc: spacemit: handle regmap_test_bits() error return

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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: a6de182daa ("rtc: spacemit: support the SpacemiT P1 RTC")
Reviewed-by: Alex Elder <elder@riscstar.com>
Signed-off-by: Surendra Singh Chouhan <kr494167@gmail.com>
Link: https://patch.msgid.link/20260724135803.81223-1-kr494167@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Surendra Singh Chouhan
2026-07-24 19:28:03 +05:30
committed by Alexandre Belloni
parent 9c48a53685
commit 092755367e
1 changed files with 3 additions and 2 deletions
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5
drivers/rtc/rtc-spacemit-p1.c
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@@ -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 ?: -EINVAL; /* RTC is disabled or error */
ret = regmap_bulk_read(regmap, RTC_TIME, time, sizeof(time));
if (ret)