Re: [PATCH 0/4] usb: chipidea: imx: add HSIC support

[Frieder Schrempf <frieder.schrempf@exceet.de>]

On 17.10.18 13:04, Frieder Schrempf wrote:
> On 17.10.18 11:56, Frieder Schrempf wrote:
[...]
>>> - System suspend/resume
>>> 1. Enable USB wakeup
>>> for i in $(find /sys -name wakeup | grep usb);do echo enabled  > 
>>> $i;echo "echo enabled > $i";done;
>>> 2. Let the system enter suspend using below command
>>> echo mem > /sys/power/state
>>> 3. And see if there is a wakeup block system entering suspend, and 
>>> check if USB HSIC works ok
>>> after system resume
>>
>> System suspend/resume seems to work fine. After resume the ethernet 
>> controller works.
>>
>> root@imxceet-solo-s-43:~# echo mem > /sys/power/state
>> PM: suspend entry (deep)
>> PM: Syncing filesystems ... done.
>> Freezing user space processes ... (elapsed 0.001 seconds) done.
>> OOM killer disabled.
>> Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
>> smsc95xx 3-1:1.0 eth1: entering SUSPEND2 mode
>> PM: suspend devices took 0.050 seconds
>> Disabling non-boot CPUs ...
>> usb 3-1: reset high-speed USB device number 2 using ci_hdrc
>> PM: resume devices took 0.590 seconds
>> OOM killer enabled.
>> Restarting tasks ... done.
>> PM: suspend exit
>> smsc95xx 3-1:1.0 eth1: link up, 100Mbps, full-duplex, lpa 0x4DE1
>> fec 2188000.ethernet eth0: Link is Up - 100Mbps/Full - flow control rx/tx
>>
>>>
>>> - Runtime suspend
>>> 1. Enable auto suspend for all USB devices, and check if USBOH3 clock 
>>> is closed,
>>> make sure do not plug any ethernet cable on the RJ45 port.
>>>
>>> /* Enable auto suspend */
>>> for i in $(find /sys -name control | grep usb);do echo auto  > 
>>> $i;echo "echo auto > $i";done;
>>
>> This doesn't work. When the port is suspended it gets into a loop of 
>> suspending/resuming endlessly. If i put two logs in 
>> ci_hdrc_imx_runtime_suspend() and ci_hdrc_imx_runtime_resume(), I get 
>> this:
>>
>> [...]
>> ci_hdrc_imx_runtime_resume:603
>> ci_hdrc_imx_runtime_suspend:574
>> ci_hdrc_imx_runtime_resume:603
>> ci_hdrc_imx_runtime_suspend:574
>> ci_hdrc_imx_runtime_resume:603
>> ci_hdrc_imx_runtime_suspend:574
>> ci_hdrc_imx_runtime_resume:603
>> ci_hdrc_imx_runtime_suspend:574
>> [...]
> 
> Ok, forget about the loop, this was caused by one of the other ports, 
> that had issues with overcurrent detection.
> 
> But still it doesn't work for the HSIC port.
> 
> The HSIC device is stuck in status "suspending" (note: "suspending" and 
> not "suspended"):
> 
> ~# cat /sys/bus/usb/devices/usb1/power/runtime_status
> suspended
> ~# cat /sys/bus/usb/devices/usb2/power/runtime_status
> suspended
> ~# cat /sys/bus/usb/devices/usb3/power/runtime_status
> active
> ~# cat /sys/bus/usb/devices/usb3/3-1/power/runtime_status
> suspending

It seems like this is a problem with the smsc95xx driver. I fixed this 
and now the device is suspending properly, when the network interface is 
down and resumes when it comes up.

I also checked the USBOH3 clock and its properly switched on and off.

What didn't work is auto suspend and resume on ethernet link down/up, 
but this seems to be a restriction of the smsc95xx/usbnet driver.

So all in all this looks good to me. Please let me know if you need any 
more information or tests.

Thanks,
Frieder