From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Anson Huang <anson.huang@nxp.com>
Cc: "a.zummo@towertech.it" <a.zummo@towertech.it>,
"linux-rtc@vger.kernel.org" <linux-rtc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
dl-linux-imx <linux-imx@nxp.com>
Subject: Re: [PATCH] rtc: snvs: make sure clock is enabled for interrupt handle
Date: Fri, 11 Jan 2019 15:31:41 +0100 [thread overview]
Message-ID: <20190111143141.GC2547@piout.net> (raw)
In-Reply-To: <1547190255-9388-1-git-send-email-Anson.Huang@nxp.com>
Hi,
On 11/01/2019 07:09:02+0000, Anson Huang wrote:
> During system suspend, the SNVS RTC's clock will be disabled in
> noirq suspend phase, but SNVS RTC's alarm interrupt could still
> arrive, system will hang if SNVS RTC driver tries to access register
> without clock enabled, this patch fixes the issue of this scenario.
>
Are you sure this is the real issue? I don't think the handler can be
called before the resume_noirq callback. Isn't the issue that your clock
driver has not yet resumed by the time you call the rtc driver
resume_noirq callback ?
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> drivers/rtc/rtc-snvs.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
> index b2483a7..0b9eff1 100644
> --- a/drivers/rtc/rtc-snvs.c
> +++ b/drivers/rtc/rtc-snvs.c
> @@ -239,6 +239,9 @@ static irqreturn_t snvs_rtc_irq_handler(int irq, void *dev_id)
> u32 lpsr;
> u32 events = 0;
>
> + if (data->clk)
> + clk_enable(data->clk);
> +
Anyway, won't that need a clk_prepare_enable because it has been
clk_disable_unprepare in suspend_noirq? And this is something you can
not do in atomic context
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
next prev parent reply other threads:[~2019-01-11 15:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-11 7:09 [PATCH] rtc: snvs: make sure clock is enabled for interrupt handle Anson Huang
2019-01-11 14:31 ` Alexandre Belloni [this message]
2019-01-14 2:10 ` Anson Huang
2019-02-05 22:10 ` Alexandre Belloni
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190111143141.GC2547@piout.net \
--to=alexandre.belloni@bootlin.com \
--cc=a.zummo@towertech.it \
--cc=anson.huang@nxp.com \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rtc@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).