2018-12-04 03:18:48

by Anson Huang

Subject: [PATCH V2] ARM: imx: update the cpu power up timing setting on i.mx6sx

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 <[email protected]>
Reviewed-by: Fabio Estevam <[email protected]>
---
arch/arm/mach-imx/cpuidle-imx6sx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

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);
--
2.7.4

2018-12-06 01:57:08

by Shawn Guo

Subject: Re: [PATCH V2] ARM: imx: update the cpu power up timing setting on i.mx6sx

On Tue, Dec 04, 2018 at 03:17:45AM +0000, Anson Huang 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 <[email protected]>
> Reviewed-by: Fabio Estevam <[email protected]>

Applied, thanks.