linux-kernel - Re: [PATCH] soc: mediatek: PMIC wrap: Enable STAUPD_PRD before WDT_SRC

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: <CAGS+omBc2XVESu1t+_iKj1gTk-7JVDK1KDoQEJR_-wcL4m0qWg@mail.gmail.com>
Date:	Thu, 31 Dec 2015 22:19:03 +0800
From:	Daniel Kurtz <djkurtz@...omium.org>
To:	Henry Chen <henryc.chen@...iatek.com>
Cc:	Matthias Brugger <matthias.bgg@...il.com>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"moderated list:ARM/Mediatek SoC support" 
	<linux-mediatek@...ts.infradead.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] soc: mediatek: PMIC wrap: Enable STAUPD_PRD before
 WDT_SRC_EN enabled.

On Wed, Dec 30, 2015 at 8:36 PM, Henry Chen <henryc.chen@...iatek.com> wrote:
>
> The STAUPD_TRIG will be enable when WDT_INT enable on probe function, if
> doesn't enable STAUPD_PRD together, interrupt will be triggered because
> STAUPD timeout. To avoid unexpected interrupt, enable periodic status
> update which will be updated to PMIC every selected time period.

Sorry, I don't really understand this.

What exactly is triggering the unexpected watchdog interrupt (WDT_INT)?

How does setting STAUPD_PRD disable this "unexpected interrupt"?

>From the MT8173 Datasheet, I can see that the value written to
STAUPD_PRD is the "periodic status update timing (period)".

> Signed-off-by: Henry Chen <henryc.chen@...iatek.com>
> ---
>  drivers/soc/mediatek/mtk-pmic-wrap.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> index a8cde17..6e5c20f 100644
> --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
> @@ -904,6 +904,11 @@ static int pwrap_probe(struct platform_device *pdev)
>                 return -ENODEV;
>         }
>
> +       /*
> +        * Enable periodic status update which will be updated to PMIC
> +        * every selected time period.
> +        */
> +       pwrap_writel(wrp, 0x5, PWRAP_STAUPD_PRD);

nit: Perhaps use a define for 5, and specify the real period value.
Something like this:

#define PWRAP_STAUPD_98_5US  5


>         /* Initialize watchdog, may not be done by the bootloader */
>         pwrap_writel(wrp, 0xf, PWRAP_WDT_UNIT);
>         pwrap_writel(wrp, 0xffffffff, PWRAP_WDT_SRC_EN);
> --
> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/