From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Brian Norris <briannorris@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeffy Chen <jeffy.chen@rock-chips.com>,
Matthias Kaehlcke <mka@chromium.org>
Subject: Re: [PATCH] rtc: report time-retrieval errors when updating alarm
Date: Mon, 21 Oct 2019 18:11:13 +0200 [thread overview]
Message-ID: <20191021161113.GZ3125@piout.net> (raw)
In-Reply-To: <20180521164222.149896-1-briannorris@chromium.org>
Hello Brian,
On 21/05/2018 09:42:22-0700, Brian Norris wrote:
> __rtc_read_time() can fail (e.g., if the RTC uses an unreliable medium).
> When it does, we don't report the error, but instead calculate a
> 1-second alarm based on the potentially-garbage 'tm' (in practice,
> __rtc_read_time() zeroes out the time first, so it's likely to still be
> all 0).
>
> Let's propagate the error instead.
>
I submitted
https://lore.kernel.org/linux-rtc/20191021155631.3342-2-alexandre.belloni@bootlin.com/T/#u
to solve this after looking at all the implication checking the return
value of __rtc_read_time had.
> Signed-off-by: Brian Norris <briannorris@chromium.org>
> ---
> drivers/rtc/interface.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> index 7cbdc9228dd5..a4bdd8b5fe2e 100644
> --- a/drivers/rtc/interface.c
> +++ b/drivers/rtc/interface.c
> @@ -555,7 +555,9 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> struct rtc_time tm;
> ktime_t now, onesec;
>
> - __rtc_read_time(rtc, &tm);
> + err = __rtc_read_time(rtc, &tm);
> + if (err)
> + goto out;
> onesec = ktime_set(1, 0);
> now = rtc_tm_to_ktime(tm);
> rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
> --
> 2.17.0.441.gb46fe60e1d-goog
>
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
next prev parent reply other threads:[~2019-10-21 16:11 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-21 16:42 [PATCH] rtc: report time-retrieval errors when updating alarm Brian Norris
2019-10-21 16:11 ` Alexandre Belloni [this message]
2019-10-21 17:20 ` Brian Norris
2019-10-21 17:48 ` Alexandre Belloni
2019-10-21 18:08 ` Brian Norris
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