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| author | Vaibhav Jain <vaibhav@linux.vnet.ibm.com> | 2017-05-19 15:35:09 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-13 19:50:15 +0200 |
| commit | 756b0f10ff34e4b8fdfbb7ba62c4c92f33ec011b (patch) | |
| tree | f1f411967f2c41d1367bfa713588035234b05650 /drivers/rtc | |
| parent | 2368800e4f26172a7c217fc2257d05946866e24c (diff) | |
| download | linux-stable-756b0f10ff34e4b8fdfbb7ba62c4c92f33ec011b.tar.gz linux-stable-756b0f10ff34e4b8fdfbb7ba62c4c92f33ec011b.tar.bz2 linux-stable-756b0f10ff34e4b8fdfbb7ba62c4c92f33ec011b.zip | |
rtc: opal: Handle disabled TPO in opal_get_tpo_time()
[ Upstream commit 6dc1cf6f932bb0ea4d8f5e913a0a401ecacd2f03 ]
On PowerNV platform when Timed-Power-On(TPO) is disabled, read of
stored TPO yields value with all date components set to '0' inside
opal_get_tpo_time(). The function opal_to_tm() then converts it to an
offset from year 1900 yielding alarm-time == "1900-00-01
00:00:00". This causes problems with __rtc_read_alarm() that
expecting an offset from "1970-00-01 00:00:00" and returned alarm-time
results in a -ve value for time64_t. Which ultimately results in this
error reported in kernel logs with a seemingly garbage value:
"rtc rtc0: invalid alarm value: -2-1--1041528741
2005511117:71582844:32"
We fix this by explicitly handling the case of all alarm date-time
components being '0' inside opal_get_tpo_time() and returning -ENOENT
in such a case. This signals generic rtc that no alarm is set and it
bails out from the alarm initialization flow without reporting the
above error.
Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
Reported-by: Steve Best <sbest@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-opal.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c index 229dd2fe8f45..c6b0c7ed7a30 100644 --- a/drivers/rtc/rtc-opal.c +++ b/drivers/rtc/rtc-opal.c @@ -150,6 +150,16 @@ static int opal_get_tpo_time(struct device *dev, struct rtc_wkalrm *alarm) y_m_d = be32_to_cpu(__y_m_d); h_m_s_ms = ((u64)be32_to_cpu(__h_m) << 32); + + /* check if no alarm is set */ + if (y_m_d == 0 && h_m_s_ms == 0) { + pr_debug("No alarm is set\n"); + rc = -ENOENT; + goto exit; + } else { + pr_debug("Alarm set to %x %llx\n", y_m_d, h_m_s_ms); + } + opal_to_tm(y_m_d, h_m_s_ms, &alarm->time); exit: |