From: Lucas Stach <l.stach@pengutronix.de>
To: Anson Huang <anson.huang@nxp.com>,
Dong Aisheng <dongas86@gmail.com>, Stefan Agner <stefan@agner.ch>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"robh+dt@kernel.org" <robh+dt@kernel.org>,
dl-linux-imx <linux-imx@nxp.com>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
Fabio Estevam <fabio.estevam@nxp.com>,
"shawnguo@kernel.org" <shawnguo@kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/7] ARM: imx: add timer stop flag to ARM power off state
Date: Tue, 09 Jan 2018 11:13:23 +0100 [thread overview]
Message-ID: <1515492803.12538.29.camel@pengutronix.de> (raw)
In-Reply-To: <AM3PR04MB13155287E5AAAF5407AF68A6F5100@AM3PR04MB1315.eurprd04.prod.outlook.com>
Am Dienstag, den 09.01.2018, 09:25 +0000 schrieb Anson Huang:
>
> Best Regards!
> Anson Huang
>
>
> > -----Original Message-----
> > From: Dong Aisheng [mailto:dongas86@gmail.com]
> > Sent: 2018-01-09 5:23 PM
> > To: Stefan Agner <stefan@agner.ch>
> > Cc: shawnguo@kernel.org; kernel@pengutronix.de; Fabio Estevam
> > <fabio.estevam@nxp.com>; robh+dt@kernel.org; mark.rutland@arm.com;
> > linux-arm-kernel@lists.infradead.org; devicetree@vger.kernel.org;
> > linux-
> > kernel@vger.kernel.org; Anson Huang <anson.huang@nxp.com>; dl-
> > linux-imx
> > <linux-imx@nxp.com>
> > Subject: Re: [PATCH 1/7] ARM: imx: add timer stop flag to ARM power
> > off state
> >
> > On Tue, Jan 02, 2018 at 05:42:17PM +0100, Stefan Agner wrote:
> > > When the CPU is in ARM power off state the ARM architected timers
> > > are
> > > stopped. The flag is already present in the higher power WAIT
> > > mode.
> > >
> > > This allows to use the ARM generic timer on i.MX 6UL/6ULL SoC.
> > > Without the flag the kernel freezes when the timer enters the
> > > first
> > > time ARM power off mode.
> > >
> > > Cc: Anson Huang <anson.huang@nxp.com>
> > > Signed-off-by: Stefan Agner <stefan@agner.ch>
> >
> > It seems ok at my side.
> > Did you meet the real issue? If yes, how to reproduce?
> >
> > Both mx6sx and mx6ul are using GPT which do not need that flag,
> > suppose we
> > should remove it, right?
> > Anson can help confirm it.
>
> For UP system like i.MX6SX, we do NOT enable "cortex-a9-twd-timer",
> so local
> timer is NOT used, GPT is used instead, GPT's clock is NOT disabled
> when cpuidle,
> so I think we should remove all these Timer stop flag for 6SX
> CPUIDLE.
It's correct to set the flag even on UP systems, as the flag means the
CPU _local_ timer is stopped in this sleep mode. Also there are systems
out there which are using the TWD on UP, as it operates at a higher
frequency leading to better wakeup granularity.
Regards,
Lucas
next prev parent reply other threads:[~2018-01-09 10:13 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-02 16:42 [PATCH 1/7] ARM: imx: add timer stop flag to ARM power off state Stefan Agner
2018-01-02 16:42 ` [PATCH 2/7] ARM: dts: imx6ul: update i.MX 6UltraLite iomux headers Stefan Agner
2018-01-05 16:45 ` Rob Herring
2018-01-06 10:47 ` Stefan Agner
2018-01-08 1:37 ` Andy Duan
2018-01-09 9:24 ` Dong Aisheng
2018-01-02 16:42 ` [PATCH 3/7] ARM: dts: imx6ull: add additional pinfunc defines for i.MX 6ULL Stefan Agner
[not found] ` <20180102164223.15230-3-stefan-XLVq0VzYD2Y@public.gmane.org>
2018-01-05 16:49 ` Rob Herring
2018-01-07 9:52 ` Stefan Agner
[not found] ` <b183c2a38596cd3f3726777c79e027f9-XLVq0VzYD2Y@public.gmane.org>
2018-01-09 9:30 ` Dong Aisheng
2018-01-02 16:42 ` [PATCH 4/7] ARM: dts: imx6ul: add interrupt of virt-capable GIC Stefan Agner
2018-01-02 16:42 ` [PATCH 5/7] ARM: dts: imx6ul: add ARM architected timer Stefan Agner
[not found] ` <20180102164223.15230-5-stefan-XLVq0VzYD2Y@public.gmane.org>
2018-01-09 9:34 ` Dong Aisheng
2018-01-09 13:18 ` Stefan Agner
2018-01-02 16:42 ` [PATCH 6/7] ARM: dts: imx6ull: add IOMUXC SNVS instance Stefan Agner
2018-01-09 9:35 ` Dong Aisheng
[not found] ` <20180102164223.15230-1-stefan-XLVq0VzYD2Y@public.gmane.org>
2018-01-02 16:42 ` [PATCH 7/7] ARM: dts: imx6ull: add UART8 support Stefan Agner
2018-01-09 9:38 ` Dong Aisheng
2018-01-09 9:22 ` [PATCH 1/7] ARM: imx: add timer stop flag to ARM power off state Dong Aisheng
2018-01-09 9:25 ` Anson Huang
2018-01-09 10:13 ` Lucas Stach [this message]
[not found] ` <1515492803.12538.29.camel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2018-01-09 13:37 ` Stefan Agner
2018-01-09 14:04 ` Lucas Stach
2018-01-09 22:21 ` Stefan Agner
2018-01-09 13:22 ` Stefan Agner
2018-01-10 17:48 ` Lucas Stach
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