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>You can't have a USB hub that can't be controlled over USB, it wouldn't be able to work at all. The spec requires hubs to be active devices that show up on the

by gsich 3y ago

>You can't have a USB hub that can't be controlled over USB, it wouldn't be able to work at all. The spec requires hubs to be active devices that show up on the bus and that can handle requests from the host, such as selective suspend or port power control. Irrelevant in this context. >Whether your hub actually offers a physical ability to turn off power of individual ports is another matter. And the only matter that counts when it comes to "controllable" USB hubs. If I can't "control" the USB hub with uhubctl (or any other tool) it's not controllable.

seba_dos1 3y ago
You're replying to my comment about an interface used to control such hubs, so it's what you are saying that's irrelevant in this context. All hubs have means to control them via USB in-band (there are other things to control there than power too), and hubs that do support power switching can be controlled this way, so there's no need to use external interfaces like I2C unless you want to control such hub externally (not from the USB host), which is what this thread was about.
- gsich 3y ago
  >You're replying to my comment about an interface used to control such hubs, so it's what you are saying that's irrelevant in this context. Yes. An interface. Because not all hubs can be controlled in-band. Maybe you have a different definition of "control". >All hubs have means to control them via USB in-band (there are other things to control there than power too), and hubs that do support power switching can be controlled this way, so there's no need to use external interfaces like I2C unless you want to control such hub externally (not from the USB host), which is what this thread was about. This is wrong though. I can't control my hub. Doesn't matter that there are some other stuff I could theoretically control. (or the OS does without my intervention) Yes. The Github link is about how to control a USB hub via I2C. From the description: >Have you ever wanted to control USB devices using an Arduino, ESP32, or Raspberry Pi? with the i2C USB Hub, you can! Turn on or off ports of the USB hub using i2c, as well as control indicator lights and set current limits per-port. So you saying, that you could do that in-band is wrong, because not all hubs can be controlled in-band. Or the easy definition: no port control == not controllable.
  - seba_dos1 3y ago
    > This is wrong though. Nothing's wrong there and you're just playing with semantics to not admit your misunderstanding. All hubs have an in-band control interface available that can be used by them to implement port power control, period. > The Github link is about how to control a USB hub via I2C. No, it points to a hardware design for a very specific hub that implemented its port power control via I2C. Usually hubs don't have any I2C interface at all as they don't need one, regardless of whether they do port control or not.
    - gsich 3y ago
      >Nothing's wrong there and you're just playing with semantics to not admit your misunderstanding. All hubs have an in-band control interface available that can be used by them to implement port power control, period. You want to make it about semantics because you think that "control" means something different then what it means. There are hubs that can't be controlled that way. Period. ./uhubctl No compatible devices detected! Run with -h to get usage info. Feel free to tell me how I can get those uncontrollable hubs compatible.
      - seba_dos1 3y ago
        This is completely irrelevant to what this subthread is about and you would know that if you had read it again instead of trying to insist that you're right.
        gsich 3y ago
        No it's not. To go back to your original statement: >USB hubs are controllable via USB, so I guess this is for cases where your hub is connected to a device you don't control. This is not a generally true. I gave an example of an uncontrollable hub you deemed irrelevant. What is control if it's not controlling the USB hub? It's not "the kernel does something which requires no user input".
        3y ago

by gsich 3y ago

seba_dos1 3y ago

You're replying to my comment about an interface used to control such hubs, so it's what you are saying that's irrelevant in this context. All hubs have means to control them via USB in-band (there are other things to control there than power too), and hubs that do support power switching can be controlled this way, so there's no need to use external interfaces like I2C unless you want to control such hub externally (not from the USB host), which is what this thread was about.

gsich 3y ago
>You're replying to my comment about an interface used to control such hubs, so it's what you are saying that's irrelevant in this context. Yes. An interface. Because not all hubs can be controlled in-band. Maybe you have a different definition of "control". >All hubs have means to control them via USB in-band (there are other things to control there than power too), and hubs that do support power switching can be controlled this way, so there's no need to use external interfaces like I2C unless you want to control such hub externally (not from the USB host), which is what this thread was about. This is wrong though. I can't control my hub. Doesn't matter that there are some other stuff I could theoretically control. (or the OS does without my intervention) Yes. The Github link is about how to control a USB hub via I2C. From the description: >Have you ever wanted to control USB devices using an Arduino, ESP32, or Raspberry Pi? with the i2C USB Hub, you can! Turn on or off ports of the USB hub using i2c, as well as control indicator lights and set current limits per-port. So you saying, that you could do that in-band is wrong, because not all hubs can be controlled in-band. Or the easy definition: no port control == not controllable.
- seba_dos1 3y ago
  > This is wrong though. Nothing's wrong there and you're just playing with semantics to not admit your misunderstanding. All hubs have an in-band control interface available that can be used by them to implement port power control, period. > The Github link is about how to control a USB hub via I2C. No, it points to a hardware design for a very specific hub that implemented its port power control via I2C. Usually hubs don't have any I2C interface at all as they don't need one, regardless of whether they do port control or not.
  - gsich 3y ago
    >Nothing's wrong there and you're just playing with semantics to not admit your misunderstanding. All hubs have an in-band control interface available that can be used by them to implement port power control, period. You want to make it about semantics because you think that "control" means something different then what it means. There are hubs that can't be controlled that way. Period. ./uhubctl No compatible devices detected! Run with -h to get usage info. Feel free to tell me how I can get those uncontrollable hubs compatible.
    - seba_dos1 3y ago
      This is completely irrelevant to what this subthread is about and you would know that if you had read it again instead of trying to insist that you're right.
      - gsich 3y ago
        No it's not. To go back to your original statement: >USB hubs are controllable via USB, so I guess this is for cases where your hub is connected to a device you don't control. This is not a generally true. I gave an example of an uncontrollable hub you deemed irrelevant. What is control if it's not controlling the USB hub? It's not "the kernel does something which requires no user input".
        3y ago