[Letux-kernel] power management problems in ehci-omap

Michael Nazzareno Trimarchi michael at amarulasolutions.com
Sun Feb 4 12:34:03 CET 2018


Hi

On Sun, Feb 4, 2018 at 12:07 PM, H. Nikolaus Schaller <hns at goldelico.com> wrote:
> Hi Michael,
>
>> Am 04.02.2018 um 11:55 schrieb Michael Nazzareno Trimarchi <michael at amarulasolutions.com>:
>>
>> Hi Andreas
>>
>> On Sun, Feb 4, 2018 at 11:50 AM, Andreas Kemnade <andreas at kemnade.info> wrote:
>>> Hi,
>>>
>>> On Sun, 4 Feb 2018 09:43:45 +0100
>>> Michael Nazzareno Trimarchi <michael at amarulasolutions.com> wrote:
>>>
>>>> Hi Andreas
>>>>
>>>> On Sun, Feb 4, 2018 at 9:38 AM, Andreas Kemnade <andreas at kemnade.info> wrote:
>>>>> On Sun, 4 Feb 2018 00:10:50 +0100
>>>>> Michael Nazzareno Trimarchi <michael at amarulasolutions.com> wrote:
>>>>>
>>>>>> Hi
>>>>>>
>>>>>> On Sun, Feb 4, 2018 at 12:03 AM, Andreas Kemnade <andreas at kemnade.info> wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> I booted a 4.15 kernel without udev and loaded modules piece by piece to analyze
>>>>>>> pm problems. modprobe ehci-omap increases current by around 35mA and
>>>>>>> also rmmod ehci-omap does not let it go down at all.
>>>>>>>
>>>>>>> I expect that removing hardware does the same thing
>>>>> nonsense sentence from me, was to tired. I would expect that removing the modules
>>>>> properly powers down the device.
>>>>>>>
>>>>>>> Also suspend current increases by around 15mA if that module is loaded.
>>>>>>> I tested with having everything disabled which is attached to that usb bus.
>>>>>>>
>>>>>>
>>>>>> Do you have an LTE connected to the usb?
>>>>>>
>>>>> Yes, there is a UMTS modem attached, but it was off during the tests.
>>>>> It did not enumerate on the modem.
>>>>>
>>>>
>>>> Just to understand if the suspend current drop was connected to the
>>>> suspend of lte modem on your side.
>>>> So you don't have anything connected on usb bus?
>>>>
>>> Suspend current is increased when the ehci-omap module is loaded
>>> in comparison to the state. I tested with the modem disabled, so there
>>> is nothing on the bus. Increased suspend current is one thing,
>>> current_before_modprobe_ehci_omap != current_after_rmmod_ehci_omap.
>>>
>>> I am testing with init=some_testscript.sh, so no userspace
>>> is doing strange things. No module autoload or something.
>>>
>>
>> How many port are configured and how is the phy part connected to the
>> ehci controller?
>> Can you point me the schematic page?
>
> it is essentially a copy&paste from BeagleBoard XM.
>
> Schematics of the GTA04 are here:
>
>         http://projects.goldelico.com/p/gta04-main/downloads/48/
>
> USB PHY is on page 9.
>

I see. GPIO174 is controlled by you during boot or connected to the dts?
I don't find in mainline the connection to the physical and it's own
programming.
Can you check if the phy is in reset when module is remove?

Michael


> BR,
> Nikolaus
>
>>
>> michael
>>
>>
>>> Regards,
>>> Andreas
>>
>>
>>
>> --
>> | Michael Nazzareno Trimarchi                     Amarula Solutions BV |
>> | COO  -  Founder                                      Cruquiuskade 47 |
>> | +31(0)851119172                                 Amsterdam 1018 AM NL |
>> |                  [`as] http://www.amarulasolutions.com               |
>> _______________________________________________
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>



-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |


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