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| author | Mateusz Jończyk <mat.jonczyk@o2.pl> | 2021-12-10 21:01:25 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2021-12-16 21:50:06 +0100 |
| commit | 0dd8d6cb9eddfe637bcd821bbfd40ebd5a0737b9 (patch) | |
| tree | a74379236696860c6a100849294321e8d75b3435 /drivers/rtc | |
| parent | d35786b3a28dee20b12962ae2dd365892a99ed1a (diff) | |
| download | linux-0dd8d6cb9eddfe637bcd821bbfd40ebd5a0737b9.tar.gz linux-0dd8d6cb9eddfe637bcd821bbfd40ebd5a0737b9.tar.bz2 linux-0dd8d6cb9eddfe637bcd821bbfd40ebd5a0737b9.zip | |
rtc: Check return value from mc146818_get_time()
There are 4 users of mc146818_get_time() and none of them was checking
the return value from this function. Change this.
Print the appropriate warnings in callers of mc146818_get_time() instead
of in the function mc146818_get_time() itself, in order not to add
strings to rtc-mc146818-lib.c, which is kind of a library.
The callers of alpha_rtc_read_time() and cmos_read_time() may use the
contents of (struct rtc_time *) even when the functions return a failure
code. Therefore, set the contents of (struct rtc_time *) to 0x00,
which looks more sensible then 0xff and aligns with the (possibly
stale?) comment in cmos_read_time:
/*
* If pm_trace abused the RTC for storage, set the timespec to 0,
* which tells the caller that this RTC value is unusable.
*/
For consistency, do this in mc146818_get_time().
Note: hpet_rtc_interrupt() may call mc146818_get_time() many times a
second. It is very unlikely, though, that the RTC suddenly stops
working and mc146818_get_time() would consistently fail.
Only compile-tested on alpha.
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-alpha@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210200131.153887-4-mat.jonczyk@o2.pl
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-cmos.c | 9 | ||||
| -rw-r--r-- | drivers/rtc/rtc-mc146818-lib.c | 2 |
2 files changed, 9 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c index dc3f8b0dde98..d0f58cca5c20 100644 --- a/drivers/rtc/rtc-cmos.c +++ b/drivers/rtc/rtc-cmos.c @@ -222,6 +222,8 @@ static inline void cmos_write_bank2(unsigned char val, unsigned char addr) static int cmos_read_time(struct device *dev, struct rtc_time *t) { + int ret; + /* * If pm_trace abused the RTC for storage, set the timespec to 0, * which tells the caller that this RTC value is unusable. @@ -229,7 +231,12 @@ static int cmos_read_time(struct device *dev, struct rtc_time *t) if (!pm_trace_rtc_valid()) return -EIO; - mc146818_get_time(t); + ret = mc146818_get_time(t); + if (ret < 0) { + dev_err_ratelimited(dev, "unable to read current time\n"); + return ret; + } + return 0; } diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c index c186c8c4982b..ccd974b8a75a 100644 --- a/drivers/rtc/rtc-mc146818-lib.c +++ b/drivers/rtc/rtc-mc146818-lib.c @@ -24,7 +24,7 @@ again: /* Ensure that the RTC is accessible. Bit 6 must be 0! */ if (WARN_ON_ONCE((CMOS_READ(RTC_VALID) & 0x40) != 0)) { spin_unlock_irqrestore(&rtc_lock, flags); - memset(time, 0xff, sizeof(*time)); + memset(time, 0, sizeof(*time)); return -EIO; } |