Re: query EHCI 3ms SUSPEND

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

>From: David Brownell [mailto:david-b@xxxxxxxxxxx]
>> If I check on Fedora, I don't see that happening rather SOFs keep going
>> to the device?
>So far as software is concerned, once a port gets enabled it is
>expected to issue SOFs unless it gets explicitly told to suspend.

1) So, Is it that from sysfs user interface on USB host we suspend the port (EHCI.PORTSC) so that devices see no activity on the bus and get suspended? 

2) Please advise if the following is the right way to do a suspend of EHCI port with device enumerated:
echo -n 2> /sys/devices/platform/ehci.0/usb1/1-2/1-2:1.0/power/state
and I can see that SOFs have stopped from EHCI. Fine.

I tried to resume the device with:
echo -n 0> /sys/devices/platform/ehci.0/usb1/1-2/1-2:1.0/power/state

and I see that device goes to Companion Controller and fails enumeration.

What should be the correct behavior for Selective suspend/resume for the attached device? 
>- Dave

SF.Net email is sponsored by: 
Check out the new Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
To unsubscribe, use the last form field at:

[Home]     [Video for Linux]     [Photo]     [Yosemite Forum]     [Yosemite Photos]    [Video Projectors]     [PDAs]     [Hacking TiVo]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Devices]     [Big List of Linux Books]     [Free Dating]

  Powered by Linux