For old style drivers, call a call to ioctl(..., RTC_ALM_SET, ...):
- char/ds1302.c will always return -EINVAL
- char/genrtc.c: will always return -EINVAL
- char/rtc.c will succeed regardless if IRQs are supported or not
- char/efirtc.c will always return -EINVAL
- input/misc/hp_sdc_rtc.c ... that ioctl code is a good lesson about
ifdefing code out and punting implementation ... and it will
always return -EINVAL
For new style rtc drivers, a call to ioctl(..., RTC_ALM_SET, ...) never
results in a call to __rtc_set_alarm, since struct rtc_wkalarm passed to
rtc_set_alarm has 'enabled' field set to 0. This means that
rtc->ops->set_alarm driver hook is never called in that ioctl. Since no
driver code interaction happens as a part of that call, using its
results to ascertain properties of the driver is not going to work. To
remedy this - use the result of RTC_AIE_ON to make the judgement.
This patch also changes ENOTTY to EINVAL as a error code value that
would tell us that IRQs are not supported. There are three reason for
this:
- As mentioned above old style driver never retunr ENOTTY for this
ioctl
- In it's code __rtc_set_alarm() returns -EINVAL if rtc->ops->set_alarm
method is not provided by the driver, so one reason for change is to
be consistent with that code path.
- A call to ioctl(..., RTC_UIE_ON, ...) will result in a call to
rtc_update_irq_enable() and then __rtc_set_alarm(), which, if IRQs
are not supported by the driver, will result in a non-zero error
code. Returning ENOTTY in that case would:
a) Not be consistent with other codepaths of
rtc_update_irq_enable, for example the check of
rtc->uie_unsupported
b) Would break update IRQ emulation code since that codpath
expects EINVAL
c) Would break test's logic for feature support detection in
the case of RTC_UIE_ON ioctl
Signed-off-by: Andrey Smirnov <[email protected]>
---
tools/testing/selftests/timers/rtctest.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/timers/rtctest.c
b/tools/testing/selftests/timers/rtctest.c
index 624bce5..0cb4628 100644
--- a/tools/testing/selftests/timers/rtctest.c
+++ b/tools/testing/selftests/timers/rtctest.c
@@ -144,11 +144,12 @@ test_READ:
retval = ioctl(fd, RTC_ALM_SET, &rtc_tm);
if (retval == -1) {
- if (errno == ENOTTY) {
+ if (errno == EINVAL) {
fprintf(stderr,
"\n...Alarm IRQs not supported.\n");
goto test_PIE;
}
+
perror("RTC_ALM_SET ioctl");
exit(errno);
}
@@ -166,6 +167,12 @@ test_READ:
/* Enable alarm interrupts */
retval = ioctl(fd, RTC_AIE_ON, 0);
if (retval == -1) {
+ if (errno == EINVAL) {
+ fprintf(stderr,
+ "\n...Alarm IRQs not supported.\n");
+ goto test_PIE;
+ }
+
perror("RTC_AIE_ON ioctl");
exit(errno);
}
--
2.5.5
