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  • sztanozs

    veterán

    válasz cigam #12660 üzenetére

    USB hibára - remélem nem gond az angol. PI2-re is ugyanúgy vonatkozik, mivel azonos chipet használnak.

    The USB driver may not be fixable, the jury is still out on this one. There are three key problems:

    1) Documentation on the Broadcom USB controller is proprietary and is not made openly available by the Raspberry Pi Foundation.

    2) The USB core for the Broadcom SoC was bought from a 3rd party, and we are told that not even Broadcom has full documentation, nor understands the driver.

    3) The Foundation has discovered that the controller and its driver expect realtime response from the ARM core, and if Linux's non-realtime scheduling doesn't respond in 1 ms, a split transaction USB event can be dropped. Not surprisingly, this occurs regularly and produces lost mouse clicks, stuck keyboard keys, etc..

    That's a pretty nasty combination of problems, and it means that assuming that it's fixable may not be a safe prediction. We'll have to wait and see.

    For the time being though, USB and networking (which is implemented over USB) have a large catalogue of issues and incompatibilities. All boards have this inherent problem but YMMV on whether the issues bite you, as it depends on exactly what devices you have connnected and what you're doing with the board.

    A kernel válaszadási képességen jelentősen javítottak, de még mindig előfordulnak problémák - főleg, ha olyan eszközt használunk, aminek kell a realtime válasz (bulk transfer módban működő USB2.0 eszközök) én nagy az adatforgalmi igénye. Amennyiben az eszköz nem kezeli jól a dobott vagy részleges csomagokat, akkor könnyen behal a drivere.

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