-----Original Message-----
From: Peng Fan
Sent: Thursday, December 28, 2017 5:09 PM
To: shawnguo at kernel.org
Cc: linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org;
van.freenix at gmail.com; Peng Fan [off-list ref]; Sascha Hauer
[off-list ref]; Fabio Estevam [off-list ref]; A.s.
Dong [off-list ref]; Russell King [off-list ref]
Subject: [PATCH V3] ARM: imx: use outer_disable/resume for low power

Use outer_disable/resume for suspend/resume and low power idle.
With the two APIs used, code could be easy to extend to introduce
l2c_write_sec for i.MX platforms when moving Linux Kernel runs in non-secure
world.

The cache sync operation and l2c310_early_resume in suspend-imx6.S are kept.
According to PL310 TRM for dormant mode: "The external power controller
asserts the reset. Ensure the cache controller is placed back into run mode prior
to the L1 masters.". So keep l2c310_early_resume.

Another reason is alought L2 controller lose power, L2 memory not lose power.
If l2c310_early_resume removed, outer_resume will do invalidation which may
corrupt data. To keep safe, the cache sync operation is also kept.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Fabio Estevam <redacted>
Cc: Dong Aisheng <aisheng.dong@nxp.com>
Cc: Russell King <linux@armlinux.org.uk>
---

V3:
 Continue fix 6SX low power idle. Because L2 memory not lose power,
outer_disable seems not clearly flush all the data or flush l1 -> flush l2  ->cache
sync must be followed, outer_resume will invalidate  the cache, which corrupt
data and cause issues. So in V3, only  add outer_disable/resume to make it
simple.
 Add more commit log.
 Based on Shawn/for-next.
V2:
  Fix 6SX booting. The V1 patch does not take 6SX low power idle into
  consideration.

 arch/arm/mach-imx/cpuidle-imx6sx.c | 2 ++
 arch/arm/mach-imx/pm-imx6.c        | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/arm/mach-imx/cpuidle-imx6sx.c b/arch/arm/mach-

imx/cpuidle-imx6sx.c
index c5a5c3a70ab1..b35841d133dc 100644

--- a/arch/arm/mach-imx/cpuidle-imx6sx.c
+++ b/arch/arm/mach-imx/cpuidle-imx6sx.c

@@ -49,7 +49,9 @@ static int imx6sx_enter_wait(struct cpuidle_device *dev,
 		cpu_pm_enter();
 		cpu_cluster_pm_enter();

+		outer_disable();
 		cpu_suspend(0, imx6sx_idle_finish);
+		outer_resume();

 		cpu_cluster_pm_exit();
 		cpu_pm_exit();

diff --git a/arch/arm/mach-imx/pm-imx6.c b/arch/arm/mach-imx/pm-imx6.c
index ecdf071653d4..153a0afc7645 100644
--- a/arch/arm/mach-imx/pm-imx6.c
+++ b/arch/arm/mach-imx/pm-imx6.c

@@ -392,8 +392,10 @@ static int imx6q_pm_enter(suspend_state_t state)
 			imx6_enable_rbc(true);
 		imx_gpc_pre_suspend(true);
 		imx_anatop_pre_suspend();
+		outer_disable();
 		/* Zzz ... */
 		cpu_suspend(0, imx6q_suspend_finish);
+		outer_resume();
 		if (cpu_is_imx6q() || cpu_is_imx6dl())
 			imx_smp_prepare();
 		imx_anatop_post_resume();
--

2.14.1