MLK-11511 ARM: imx: force ARM into wfi during LPSR enter

During stress test of LPSR using RTC alarm, sometimes
RTC alarm fail to fire, the control register(offset 0x38)
is changed and RTC alarm is disabled, according to
design team, when enter LPSR with programming SNVS
to shutdown PMIC, SNVS need some time to finish power
down process, better to put ARM into wfi during this
window.

Signed-off-by: Anson Huang <b20788@freescale.com>

diff --git a/arch/arm/mach-imx/suspend-imx7.S b/arch/arm/mach-imx/suspend-imx7.S
index d8da34c..566a49e 100644 (file)
--- a/arch/arm/mach-imx/suspend-imx7.S
+++ b/arch/arm/mach-imx/suspend-imx7.S
@@ -504,6 +504,11 @@ ENTRY(imx7_suspend)
        orr     r7, r7, #0x60
        str     r7, [r11, #0x38]
 wait_shutdown:
+       wfi
+       nop
+       nop
+       nop
+       nop
        b       wait_shutdown
 
 ddr_only_self_refresh: