From:   Kevin Hilman <khilman@baylibre.com>
To:     Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        linux-rtc@vger.kernel.org, linux-amlogic@lists.infradead.org
Cc:     Alessandro Zummo <a.zummo@towertech.it>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Subject: Re: [PATCH v1 RFC] rtc: meson-vrtc: Use ktime_get_real_ts64() to
 get the current time
In-Reply-To: <20230320212142.2355062-1-martin.blumenstingl@googlemail.com>
References: <20230320212142.2355062-1-martin.blumenstingl@googlemail.com>
Date:   Tue, 21 Mar 2023 02:52:31 -0700
Message-ID: <7hbkkmwhwg.fsf@baylibre.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:

> The VRTC alarm register can be programmed with an amount of seconds
> after which the SoC will be woken up by the VRTC timer again. We are
> already converting the alarm time from meson_vrtc_set_alarm() to
> "seconds since 1970". This means we also need to use "seconds since
> 1970" for the current time.
>
> This fixes a problem where setting the alarm to one minute in the future
> results in the firmware (which handles wakeup) to output (on the serial
> console) that the system will be woken up in billions of seconds.
> ktime_get_raw_ts64() returns the time since boot, not since 1970. Switch
> to ktime_get_real_ts64() to fix the calculation of the alarm time and to
> make the SoC wake up at the specified date/time. Also the firmware
> (which manages suspend) now prints either 59 or 60 seconds until wakeup
> (depending on how long it takes for the system to enter suspend).
>
> Fixes: 6ef35398e827 ("rtc: Add Amlogic Virtual Wake RTC")
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

Reviewed-by: Kevin Hilman <khilman@baylibre.com>