From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anson Huang Subject: RE: [PATCH 1/7] ARM: imx: add timer stop flag to ARM power off state Date: Tue, 9 Jan 2018 09:25:59 +0000 Message-ID: References: <20180102164223.15230-1-stefan@agner.ch> <20180109092232.GA26312@b29396-OptiPlex-7040> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20180109092232.GA26312@b29396-OptiPlex-7040> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dong Aisheng , Stefan Agner Cc: "shawnguo@kernel.org" , "kernel@pengutronix.de" , Fabio Estevam , "robh+dt@kernel.org" , "mark.rutland@arm.com" , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , dl-linux-imx List-Id: devicetree@vger.kernel.org Best Regards! Anson Huang > -----Original Message----- > From: Dong Aisheng [mailto:dongas86@gmail.com] > Sent: 2018-01-09 5:23 PM > To: Stefan Agner > Cc: shawnguo@kernel.org; kernel@pengutronix.de; Fabio Estevam > ; 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 ; dl-linux-imx > > Subject: Re: [PATCH 1/7] ARM: imx: add timer stop flag to ARM power off s= tate >=20 > 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 > > Signed-off-by: Stefan Agner >=20 > It seems ok at my side. > Did you meet the real issue? If yes, how to reproduce? >=20 > Both mx6sx and mx6ul are using GPT which do not need that flag, suppose w= e > should remove it, right? > Anson can help confirm it. For UP system like i.MX6SX, we do NOT enable "cortex-a9-twd-timer", so loca= l timer is NOT used, GPT is used instead, GPT's clock is NOT disabled when cp= uidle, so I think we should remove all these Timer stop flag for 6SX CPUIDLE. Anson. >=20 > Regards > Dong Aisheng >=20 > > --- > > arch/arm/mach-imx/cpuidle-imx6sx.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c > > b/arch/arm/mach-imx/cpuidle-imx6sx.c > > index c5a5c3a70ab1..d0f14b761ff7 100644 > > --- a/arch/arm/mach-imx/cpuidle-imx6sx.c > > +++ b/arch/arm/mach-imx/cpuidle-imx6sx.c > > @@ -89,6 +89,7 @@ static struct cpuidle_driver imx6sx_cpuidle_driver = =3D { > > */ > > .exit_latency =3D 300, > > .target_residency =3D 500, > > + .flags =3D CPUIDLE_FLAG_TIMER_STOP, > > .enter =3D imx6sx_enter_wait, > > .name =3D "LOW-POWER-IDLE", > > .desc =3D "ARM power off", > > -- > > 2.15.1 > >