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Misinterpretation of Standard Causing USB Disconnects On Resume In Linux

Posted by samzenpus on from the who's-to-blame dept.

hypnosec writes "According to a new revelation by Sarah Sharp, misinterpretation of the USB 2.0 standard may have been the culprit behind USB disconnects on resume in Linux all along rather than cheap and buggy devices. According to Sharp the USB core is to blame for the disconnections rather than the devices themselves as the core doesn't wait long enough for the devices to transition from a 'resume state to U0.' The USB 2.0 standard states that system software that handles USB must provide for 10ms resume recovery time (TRSMRCY) during which it shouldn't attempt a connection to the device connected to that particular bus segment."

2 of 280 comments (clear)

  1. linux has bugs? by Anonymous Coward · · Score: 5, Interesting

    Could have fooled me, I end up spending upwards of 3 months a year fixing bugs in the base os that we ship to run our appliance on. Some of the linux subsystems still read like they were written in someone's basement even after a decade of most of the maintainers being paid a yearly salary to maintain it. God forbid you actually fix some of the crap and post fixes though that are more than ten lines long.. Its a fine way to get blacklisted.

  2. Re: not surprising by FireFury03 · · Score: 4, Interesting

    FWIW, I now have a policy of avoiding Acer like the plague and advising my customers to do the same, owing to their appealing customer support when advised that an entire product line had a bios bug.

    http://www.nexusuk.org/~steve/acer.xhtml

    TL;DR: one of their lines of laptops has a dsdt bug, I informed them, they weren't interested. I even sent them a patch, still not interested (and decided that completely ignoring my emails was the best approach). To this date they haven't released an updated bios.

    --
    http://blog.nexusuk.org