[PATCH 0/6] omap3: pm: Fixes for low power code

Kevin,

-----Original Message-----
From: Kevin Hilman [mailto:khilman at ti.com]
Sent: Thursday, March 03, 2011 6:53 AM
To: Santosh Shilimkar
Cc: linux-omap at vger.kernel.org; linux-arm-kernel at lists.infradead.org
Subject: Re: [PATCH 0/6] omap3: pm: Fixes for low power code

Hi Santosh,

Santosh Shilimkar [off-list ref] writes:

quoted

The series does below fixes to the omap3 low power code.
	1. Use supported ARMv7 instructions instead of the legacy ones
	2. Fix the MMU on sequence
	3. Fix the cache flush scenario when only L1 lost.
	4. Remove all un-necessary context save registers
	5. Disable C-bit before cache clean
	6. Use set_cr() exported API instead of custom one.

Look like good cleanups, thanks.

quoted

It's generated against mainline and tested with OMAP3630 ZOOM3.
	1. Renetion and off-mode mode in suspend - ok.
	2. Retention in idle - ok

Testing this series along with other PM changes queued up for
mainline
(my pm-core branch), this doesn't work for me on 3630/Zoom3 (but
works
fine on 3430/n900.)

Here's what I did using omap2plus_defconfig + enabling CPUidle

First tested suspend:

echo 4 > /debug/pm_debug/wakeup_timer_seconds
echo mem > /sys/power/state

then, setup UART idle/wakeup:

echo 5 > /sys/devices/platform/omap/omap_uart.0/sleep_timeout
echo 5 > /sys/devices/platform/omap/omap_uart.1/sleep_timeout
echo 5 > /sys/devices/platform/omap/omap_uart.2/sleep_timeout
echo 5 > /sys/devices/platform/omap/omap_uart.3/sleep_timeout
echo enabled >
/sys/devices/platform/serial8250.0/tty/ttyS0/power/wakeup

then enabled idle:

echo 1 > /debug/pm_debug/sleep_while_idle

As soon as I do this, it hangs.

Without your series, it's working fine for me.  Only after merging
your series it hangs.

I rebased this series against latest pm-core branch which also
has Dave's THUMB2 series merged.

After few trials I managed to reproduce the issue. With
above steps it was still working for me but with off mode
enabled, I saw a lock-up in suspend. Further debugging, I
found that one CP15 register save/restore position was
swapped which lead to this. I fixed that.

I have pushed the rebased series on below branch.

git://dev.omapzoom.org/pub/scm/santosh/kernel-omap4-base.git
pm-core-omap3-asm

Regards,
Santosh