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From:   Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
To:     linux-kernel@vger.kernel.org
Cc:     Stephen Boyd <sboyd@kernel.org>,
        John Stultz <john.stultz@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Subject: [PATCH] alarmtimer: use EOPNOTSUPP instead of ENOTSUPP
Date:   Tue,  3 Sep 2019 14:18:02 -0300
Message-Id: <20190903171802.28314-1-cascardo@canonical.com>
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Sender: linux-kernel-owner@vger.kernel.org
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ENOTSUPP is not supposed to be returned to userspace. This was found on an
OpenPower machine, where the RTC does not support set_alarm.

On that system, before the patch, a clock_nanosleep(CLOCK_REALTIME_ALARM, ...)
would result in "524 Unknown error 524", while after the patch, we get
"95 Operation not supported".

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Fixes: 1c6b39ad3f01 (alarmtimers: Return -ENOTSUPP if no RTC device is present)
---
 kernel/time/alarmtimer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 57518efc3810..b7d75a9e8ccf 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -672,7 +672,7 @@ static int alarm_timer_create(struct k_itimer *new_timer)
 	enum  alarmtimer_type type;
 
 	if (!alarmtimer_get_rtcdev())
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (!capable(CAP_WAKE_ALARM))
 		return -EPERM;
@@ -790,7 +790,7 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
 	int ret = 0;
 
 	if (!alarmtimer_get_rtcdev())
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (flags & ~TIMER_ABSTIME)
 		return -EINVAL;
-- 
2.20.1