| Message ID | 20170519100509.7807-1-vaibhav@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On 19/05/2017 at 15:35:09 +0530, Vaibhav Jain wrote: > 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> > --- > drivers/rtc/rtc-opal.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > Applied, thanks.
diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c index ea20f62..2d84e2a 100644 --- a/drivers/rtc/rtc-opal.c +++ b/drivers/rtc/rtc-opal.c @@ -142,6 +142,16 @@ 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:
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> --- drivers/rtc/rtc-opal.c | 10 ++++++++++ 1 file changed, 10 insertions(+)