[PATCH v3 02/14] mfd: max77686: Allow the max77686 rtc to wakeup the system

On 06/25/2014 07:24 PM, Doug Anderson wrote:

Hi,

On Wed, Jun 25, 2014 at 3:29 AM, Javier Martinez Canillas
[off-list ref] wrote:

quoted

Yes, the original Chrome OS 3.8 max77xxx also called the irq worker thread to
ack the interrupt.

So the real problem is that an interrupt occurs before the I2C bus controller is
resumed and so the interrupt handler is not able to access the registers over I2C.

Doug posted the following patches [0,1] that AFAIU solves the issue by making
I2C controllers to be resumed in the noirq time to ensure that drivers will be
able to use the I2C bus to handler their wakeup.

Yup, that's the solution as far as I know.  I know that in ChromeOS we
still have the extra call to the worker thread (despite the controller
waking up early), but that might be related to some other problem?

I was able to successfully suspend/resume multiple times once I woke
the i2c controller up earlier.

If you feel like adding Reviewed-by / Tested-by to my i2c patch then
feel free!  ;)

Done :)

quoted

In fact, Doug's original patch had this as a part of the commit message:

NOTE: due to wakeup ordering problems this patch alone doesn't work so
well on exynos5250-snow.  You also need something that brings the i2c
bus up before the max77686 wakeup runs.

I removed that note since I (probably wrong) thought that he didn't mean it to
be part of the commit message but just was side information.

I probably would have left that in the patch, but I'm not objecting to
you taking it out.  :)

Yes, I should had left that as well. I'll send a v4 shortly and will include the
note again.

Best regards,
Javier