On Fri, Mar 22, 2019 at 02:34:41PM +0100, Paul Kocialkowski wrote: > Le vendredi 22 mars 2019 à 08:28 -0500, Bin Liu a écrit : > > Again, think about an embedded product, if dr_mode is 'otg' which > > indicates the peripheral mode will be used at some point, when and how > > to load the gadget driver if it is not loaded automatically when Linux > > boots up? the end user doesn't have access to the console. > > Why should we think of an embedded product where the end user doesn't > have access to the console? Unless I'm mistaken, the Linux kernel > doesn't target commercial products where users are powerless in > particular, and leaves out all other use cases (which may or may not be > commercial). Okay, this will lead to an endless argument as well, so I will only explain why I mentioned embedded - AFAIK musb is only used in embedded processors. then we can stop arguing on this point... > I don't think this assumption makes any sense in Linux as a project (or > that it's sane in any context of software development for that matter, > but that's beside the point). > > > > Because no other controller requires it and therefore it's not > > > standard and violates the principle of least surprise? > > > > I know no other controller does this, but this doesn't mean it is not > > standard. > > > > > And even without taking this into account, there's also the fact that > > > while the *hardware* can do dual role, the software might decide > > > otherwise. If I don't want to have support for any gadget (at all) in > > > the end system, then why should I be forced to compile and load > > > something I don't even want to use in the first place? > > > > then dr_mode should be set to 'host' instead, you don't have to load a > > gadget if peripheral mode will never be used. > > I disagree: dr_mode describes the hardware capabilities, not what the > software does with it. I have different understanding, dr_mode describles the use case, not the hardware capabilities. And software operates the hardware accordingly based on dr_mode. Regards, -Bin.
