[meta-freescale] USB issues after moving to linux-fslc-imx_4.1-1.0.x

[Renato Caldas]

2016-10-14 10:16 GMT-04:00 Renato Caldas <rm.santos.caldas at gmail.com>:
> Hello all
>
> 2016-10-14 7:41 GMT-04:00 Renato Caldas <rm.santos.caldas at gmail.com>:
>> Hi Fabio,
>>
>> Thank you very much for the suggestion!
>>
>> It doesn't fix the problem, but it modifies it a bit:
>>
>> If a USB device is plugged in at boot time, the hub still disconnect,
>> but after a few messages the reconnection attempts stop:
>>
>> (...)
>> [    7.871127] usb 1-1: device not accepting address 7, error -71
>> [    7.877133] systemd[1]: Started Journal Service.
>> [    7.994119] usb 1-1: new high-speed USB device number 8 using ci_hdrc
>> [    8.036702] systemd-journald[108]: Received request to flush
>> runtime journal from PID 1
>> [    8.414104] usb 1-1: device not accepting address 8, error -71
>> [    8.420157] usb usb1-port1: unable to enumerate USB device
>> [    8.840514] random: nonblocking pool is initialized
>> ( END )
>>
>> If on the other end no device is plugged in, the hub now disconnects,
>> when it didn't before:
>>
>> (...)
>> [    6.647828] V_5V0_S0: disabling
>> [    6.651245] VGEN1: disabling
>> [    6.654373] V_2V5_S0: disabling
>> [    6.657735] CAN0_EN: disabling
>> [    6.660816] CAN1_EN: disabling
>> [    6.664139] ALSA device list:
>> [    6.667145]   #0: imx-wm8093
>> [    6.670215] usb 1-1: USB disconnect, device number 2
>> [    6.675217] usb 1-1.1: USB disconnect, device number 3
>> [    6.680385]   #1: imx-hdmi-soc
>> [    6.691125] VFS: Mounted root (nfs filesystem) on device 0:15.
>> [    6.697402] devtmpfs: mounted
>> (...)
>>
>> Cheers,
>>   Renato
>>
>> 2016-10-13 19:28 GMT-04:00 Fabio Estevam <festevam at gmail.com>:
>>> Hi Renato,
>>>
>>> On Thu, Oct 13, 2016 at 7:42 PM, Renato Caldas
>>> <rm.santos.caldas at gmail.com> wrote:
>>>
>>>> If I boot without any usb device connected (apart from the two
>>>> internal USB hubs) it boots successfully, but as soon as I plug in a
>>>> USB device, I get this:
>>>>
>>>> [  158.722735] usb 1-1: USB disconnect, device number 2
>>>> [  158.727768] usb 1-1.1: USB disconnect, device number 3
>>>> [  158.742031] usb usb1-port1: cannot reset (err = -32)
>>>> [  158.747696] usb usb1-port1: cannot reset (err = -32)
>>>> [  158.753047] usb usb1-port1: cannot reset (err = -32)
>>>
>>> Does it help if you pass 'usbcore.autosuspend=-1' in the kernel command line?
>
> I think I found a workaround for the issue, I got very suspicious
> about the hub disconnecting right after the various regulators were
> disabled.
>
> It turns out that if I force the "swbst" regulator(named V_5V0_S0) to
> be always enabled (setting regulator-always-on on the dts file),
> everything works fine as before. What I don't understand is that this
> regulator was disabled on the 3.x kernel, and everything worked fine
> still. I really need the schematic for this board...
>
> Another thing that is bothering me is that I don't see any reference
> to the "anatop" regulator on the 4.x dmesg... Isn't this regulator
> supposed to be detected??

I just found commit 40f737791d4dab26bf23a6331609c604142228bd for the
sabresd board, which I think explains it all:

    ARM: imx6qdl-sabresd: set swbst_reg as vbus's parent reg

    USB vbus 5V is from PMIC SWBST, so set swbst_reg as vbus's
    parent reg, it fixed a bug that the voltage of vbus is incorrect
    due to swbst_reg is disabled after boots up.

So THAT was the problem..

>
> Thanks!!
> Cheers,
>   Renato