linux-kernel - Re: [PATCH v1 RFC] rtc: meson-vrtc: Use ktime_get_real

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7hbkkmwhwg.fsf@baylibre.com>
Date:   Tue, 21 Mar 2023 02:52:31 -0700
From:   Kevin Hilman <khilman@...libre.com>
To:     Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
        linux-rtc@...r.kernel.org, linux-amlogic@...ts.infradead.org
Cc:     Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Neil Armstrong <neil.armstrong@...aro.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Subject: Re: [PATCH v1 RFC] rtc: meson-vrtc: Use ktime_get_real_ts64() to
 get the current time

Martin Blumenstingl <martin.blumenstingl@...glemail.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@...glemail.com>

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