From cd26fca202f9a720d90e00ac2dbb7c4d0544f748 Mon Sep 17 00:00:00 2001 From: Andrey Smirnov Date: Tue, 21 Jun 2016 00:22:48 -0700 Subject: [PATCH] rtc: rtctest: Change alarm IRQ support detection 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 an 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 returns 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 Signed-off-by: Alexandre Belloni --- 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); } -- 2.7.4