Hi, Andreas Bauer <andreas.bauer.nexus@xxxxxxxxx> writes: > Am Fri, Sep 17, 2021 at 08:28:16AM +0300 schrieb Felipe Balbi: > >> Have a look at other commits to get examples of how to write commits for >> upstream. You're missing your Signed-off-by, adding extra unnecessary >> spaces and making your signature show up in the commit log. All of >> these are described in kernel documentation this >> (https://www.kernel.org/doc/html/latest/process/submitting-patches.html) >> is a good starting point. > > I apologize, this was my first try at contributing based on what I > observed on this list. Will fix all mentioned points and consult the > documentation before trying again. No worries :) >> > - .bmAttributes = USB_CONFIG_ATT_SELFPOWER, >> > + .bmAttributes = 0, /* bus powered implied */ >> > + .bMaxPower = 250, /* 500mA in 2mA units */ >> >> right, your "sane" default now prevents this gadget driver from working >> behind bus powered hubs. Considering that a linux-based device is likely >> to have its own battery, this is not really a sane default. > > The linux-based battery-powered device I have here (Android) charges its > battery and is thus bus-powered while in gadget mode. that's okay. It's because of this sort of thing that we've switched to a configfs-based approach where we don't need to make assumptions about the application. That's also why the pre-composed gadgets have been moved to the "legacy" directory and we don't take changes to those anymore, unless it's a bugfix, which $subject doesn't appear to be :) > Are there really a lot of devices that use gadget mode and do NOT draw > power from the USB bus? Honest question, I don't know the answer. Finding that out is going to be pretty hard, I'm afraid. >> The default value of "self powered", seems much saner ;-) > > It violates USB specification as is for most cases I reckon. It also > maximize functionality when the host does not enforce USB spec which > mostly seems to be the case. > > Would a CONFIG option here make sense to differentiate between > bus-powered devices and self-powered ones? This would probably affect > most OTG drivers... We have configfs to cope with all of the possible variations, might want to give that a shot? https://www.kernel.org/doc/html/latest/usb/gadget_configfs.html -- balbi
