On Tue, 2010-01-05 at 22:58 +0100, Felix Schwarz wrote: > Hi, > > I'm trying to add support for my UMTS USB stick (Huawei 3765) to udev. > Until yesterday I was pretty sure that I need to patch modem-modeswitch > + adding some udev rules. > > However today I found changeset 8a993fab2f218234f06743bcc127dda61a45711b > by Dan Williams committed on Nov 23 which basically says that it is > completely wrong to use 'option-zerocd' for non-option devices. > > Dan send a reasoning before doing his revert: > http://www.spinics.net/lists/hotplug/msg03143.html > > More specifically he wrote: > "All further modem eject stuff should really handled by usb_modeswitch, > not by modem-modeswitch. I'll follow up with a patch for the rules file > saying that only Option devices should be added, and that usb_modeswitch > is really the right place for this stuff." > > I'm puzzled by that... > 1. Does that mean that you (udev upstream) declare modem-modeswitch a > dead end and everybody should look at usb_modeswitch? Yes. > 2. If a supposedly wrong string works on real hardware for real users - > how can it be wrong? You might want to argue that a parameter > 'option-zerocd' is wrong for non-option devices and we should use a > different name for the parameter... Using the 'rezero' code for ZTE devices caused real problems even though for some users it appeared to work. ZTE engineers also independently asked me to revert it. Every manufacturer uses a different eject method. You should only use the *correct* eject method for a specific device. Using the Option NV-specific 'rezero' method is simply incorrect for ZTE devices, which usually need only a simple eject. Likewise, using the 'rezero' method is incorrect for Huawei devices, because they use a different eject method. Using an incorrect eject method can confuse the device's firmware and cause it to incorrectly reenumerate, or incorrectly reply to the kernel after it has ejected the fake CD. Dan > 3. If usb_modeswitch is the way to go, are you comfortable adding this > as a dependency (by including rules which call usb_modeswitch)? -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
