ARM: imx: update the cpu power up timing setting

Message ID 1543804767-17650-1-git-send-email-Anson.Huang@nxp.com
State New
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  • ARM: imx: update the cpu power up timing setting
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Commit Message

Anson Huang Dec. 3, 2018, 2:45 a.m.
The sw2iso count should cover ARM LDO ramp-up time,
the MAX ARM LDO ramp-up time may be up to more than
100us on some boards, this patch sets sw2iso to 0xf
(~384us) which is the reset value, and it is much
more safe to cover different boards, since we have
observed that some customer boards failed with current
setting of 0x2.

Fixes: 05136f0897b5 ("ARM: imx: support arm power off in cpuidle for i.mx6sx")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
 arch/arm/mach-imx/cpuidle-imx6sx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Fabio Estevam Dec. 3, 2018, 11:42 a.m. | #1
On Mon, Dec 3, 2018 at 12:45 AM Anson Huang <anson.huang@nxp.com> wrote:
>
> The sw2iso count should cover ARM LDO ramp-up time,
> the MAX ARM LDO ramp-up time may be up to more than
> 100us on some boards, this patch sets sw2iso to 0xf
> (~384us) which is the reset value, and it is much
> more safe to cover different boards, since we have
> observed that some customer boards failed with current
> setting of 0x2.
>
> Fixes: 05136f0897b5 ("ARM: imx: support arm power off in cpuidle for i.mx6sx")
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>

Reviewed-by: Fabio Estevam <festevam@gmail.com>
Fabio Estevam Dec. 3, 2018, 12:03 p.m. | #2
On Mon, Dec 3, 2018 at 9:42 AM Fabio Estevam <festevam@gmail.com> wrote:
>
> On Mon, Dec 3, 2018 at 12:45 AM Anson Huang <anson.huang@nxp.com> wrote:
> >
> > The sw2iso count should cover ARM LDO ramp-up time,
> > the MAX ARM LDO ramp-up time may be up to more than
> > 100us on some boards, this patch sets sw2iso to 0xf
> > (~384us) which is the reset value, and it is much
> > more safe to cover different boards, since we have
> > observed that some customer boards failed with current
> > setting of 0x2.
> >
> > Fixes: 05136f0897b5 ("ARM: imx: support arm power off in cpuidle for i.mx6sx")
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
>
> Reviewed-by: Fabio Estevam <festevam@gmail.com>

Minor nit that maybe Shawn can fix while applying it: Subject should
contain imx6sx as this change only affect this SoC.
Anson Huang Dec. 4, 2018, 3:18 a.m. | #3
Hi, Fabio

Best Regards!
Anson Huang

> -----Original Message-----
> From: Fabio Estevam [mailto:festevam@gmail.com]
> Sent: 2018年12月3日 20:03
> To: Anson Huang <anson.huang@nxp.com>
> Cc: Shawn Guo <shawnguo@kernel.org>; Sascha Hauer
> <s.hauer@pengutronix.de>; Sascha Hauer <kernel@pengutronix.de>; Fabio
> Estevam <fabio.estevam@nxp.com>; Russell King - ARM Linux
> <linux@armlinux.org.uk>; moderated list:ARM/FREESCALE IMX / MXC ARM
> ARCHITECTURE <linux-arm-kernel@lists.infradead.org>; linux-kernel
> <linux-kernel@vger.kernel.org>; dl-linux-imx <linux-imx@nxp.com>
> Subject: Re: [PATCH] ARM: imx: update the cpu power up timing setting
> 
> On Mon, Dec 3, 2018 at 9:42 AM Fabio Estevam <festevam@gmail.com>
> wrote:
> >
> > On Mon, Dec 3, 2018 at 12:45 AM Anson Huang <anson.huang@nxp.com>
> wrote:
> > >
> > > The sw2iso count should cover ARM LDO ramp-up time, the MAX ARM LDO
> > > ramp-up time may be up to more than 100us on some boards, this patch
> > > sets sw2iso to 0xf
> > > (~384us) which is the reset value, and it is much more safe to cover
> > > different boards, since we have observed that some customer boards
> > > failed with current setting of 0x2.
> > >
> > > Fixes: 05136f0897b5 ("ARM: imx: support arm power off in cpuidle for
> > > i.mx6sx")
> > > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> >
> > Reviewed-by: Fabio Estevam <festevam@gmail.com>
> 
> Minor nit that maybe Shawn can fix while applying it: Subject should contain
> imx6sx as this change only affect this SoC.

I sent out the V2 patch to easy Shawn's work. Thanks.

Anson.

Patch

diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-imx/cpuidle-imx6sx.c
index 243a108..fd0053e 100644
--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c
@@ -110,7 +110,7 @@  int __init imx6sx_cpuidle_init(void)
 	 * except for power up sw2iso which need to be
 	 * larger than LDO ramp up time.
 	 */
-	imx_gpc_set_arm_power_up_timing(2, 1);
+	imx_gpc_set_arm_power_up_timing(0xf, 1);
 	imx_gpc_set_arm_power_down_timing(1, 1);
 
 	return cpuidle_register(&imx6sx_cpuidle_driver, NULL);