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| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-12-14 23:10:10 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-12-18 10:37:52 +0100 |
| commit | 54c5970df449103ec1181b92d41a2d14a79fe562 (patch) | |
| tree | a0add8400bd06b4f4d9c2045b5b3da32e9108072 | |
| parent | 609e97fe31a4d1acf7bc0411277e43a4de13db44 (diff) | |
| download | linux-stable-54c5970df449103ec1181b92d41a2d14a79fe562.tar.gz linux-stable-54c5970df449103ec1181b92d41a2d14a79fe562.tar.bz2 linux-stable-54c5970df449103ec1181b92d41a2d14a79fe562.zip | |
rtc: rv3029: remove race condition when update STATUS
There is no lock preventing concurrent access to the status register from
bth the rtc subsystem and the hwmon subsystem. Use regmap_update_bits to
ensure updating RV3029_STATUS is properly locked.
Link: https://lore.kernel.org/r/20191214221022.622482-5-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/rtc/rtc-rv3029c2.c | 34 |
1 files changed, 6 insertions, 28 deletions
diff --git a/drivers/rtc/rtc-rv3029c2.c b/drivers/rtc/rtc-rv3029c2.c index 9a0397f3dee9..421c66708138 100644 --- a/drivers/rtc/rtc-rv3029c2.c +++ b/drivers/rtc/rtc-rv3029c2.c @@ -147,19 +147,6 @@ static int rv3029_get_sr(struct device *dev, u8 *buf) return 0; } -static int rv3029_set_sr(struct device *dev, u8 val) -{ - u8 buf[1]; - int sr; - - buf[0] = val; - sr = rv3029_write_regs(dev, RV3029_STATUS, buf, 1); - dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); - if (sr < 0) - return -EIO; - return 0; -} - static int rv3029_eeprom_busywait(struct device *dev) { int i, ret; @@ -205,9 +192,9 @@ static int rv3029_eeprom_enter(struct device *dev) /* We clear the bits and retry once just in case * we had a brown out in early startup. */ - sr &= ~RV3029_STATUS_VLOW1; - sr &= ~RV3029_STATUS_VLOW2; - ret = rv3029_set_sr(dev, sr); + ret = regmap_update_bits(rv3029->regmap, RV3029_STATUS, + RV3029_STATUS_VLOW1 | + RV3029_STATUS_VLOW2, 0); if (ret < 0) return ret; usleep_range(1000, 10000); @@ -515,6 +502,7 @@ static int rv3029_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) static int rv3029_set_time(struct device *dev, struct rtc_time *tm) { + struct rv3029_data *rv3029 = dev_get_drvdata(dev); u8 regs[8]; int ret; @@ -539,19 +527,9 @@ static int rv3029_set_time(struct device *dev, struct rtc_time *tm) if (ret < 0) return ret; - ret = rv3029_get_sr(dev, regs); - if (ret < 0) { - dev_err(dev, "%s: reading SR failed\n", __func__); - return ret; - } /* clear PON bit */ - ret = rv3029_set_sr(dev, (regs[0] & ~RV3029_STATUS_PON)); - if (ret < 0) { - dev_err(dev, "%s: reading SR failed\n", __func__); - return ret; - } - - return 0; + return regmap_update_bits(rv3029->regmap, RV3029_STATUS, + RV3029_STATUS_PON, 0); } static const struct rv3029_trickle_tab_elem { |