[PATCH] ARM: OMAP2+: omap_device: drop broken RPM status update from suspend_noirq

Grygorii Strashko grygorii.strashko at ti.com
Tue Jul 25 10:41:27 PDT 2017



On 07/25/2017 03:56 AM, Tony Lindgren wrote:
> * Tony Lindgren <tony at atomide.com> [170725 00:11]:
>> * Grygorii Strashko <grygorii.strashko at ti.com> [170724 15:17]:
>>> My personal thought here is that removing of pm_runtime_set_active() will not fix
>>> root cause of the problem, but rather hide it :( and, probably, real fix will be
>>> to update USB framework to ensure that all suspend devices are also PM runtime suspend
>>> (not sure how) or add few more pm_suspend_ignore_children() calls
>>>   (for example as I've tried to do in [2], but this was unfinished).
>>>
>>> I've found very simple steps to reproduce suspend failure on am335x-evm (should also
>>> work on BBB) -  do below sequence with USB device plugged:
>>>
>>>     echo platform > /sys/power/pm_test
>>>     echo 1 > /sys/power/pm_print_times
>>>     [ echo 0 > /sys/module/printk/parameters/console_suspend ]
>>>     echo mem > /sys/power/state
>>>
>>> [   95.499685] calling  47400000.usb+ @ 733, parent: ocp
>>> [   95.504818] am335x-usb-childs 47400000.usb: runtime PM trying to suspend device but active child
>>> [   95.513750] am335x-usb-childs 47400000.usb: omap device suspend failure 0
>>>
>>> Below I've attached possible patch which converts OMAP device to
>>> use pm_runtime_force_suspend/resume().
>>
>> It seems to almost work for my PM test cases.. It seems that serial console
>> somehow won't get restored after suspend/resume cycle on omap3 though.
>>
>> The system enters off mode during suspend, and wakes up properly so I can
>> ssh to it after resume. But the serial console no longer works after resume.
>> This is with 8250-omap driver.
> 
> And FYI, on omap4 this produces a bunch of L3 irq errors on suspend.
> 

Ok. This was a risky change even if it looks obvious :(

-- 
regards,
-grygorii



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