Re: [PATCH] USB: storage: fix Huawei mode switching regression

Josua Dietze
2013-03-04T23:02:37Z

Am 04.03.2013 20:22, schrieb Bjørn Mork:
> Matthew Dharm <mdharm-usb@one-eyed-alien.net> writes:
>> The question is not one of reminding me of what I said earlier....
>> it's one of pointing people in the right direction. Frankly, some of
>> the fault for this patch lies with Greg and myself for letting it
>> through. I had just assumed that the Huawei guys had already been in
>> touch with usb-modeswitch for some reason, and that this was just an
>> optimization of existing logic (not an expansion).

I was contacted at one point by a Huawei engineer who convinced me to change the default mode-switching 'message' for all Huawei devices.
The reason was the introduction of an 'advanced' Linux driver by Huawei which requires a specific target mode. This was in October 2010.
No contact attempt since then.

>> Who is maintaining usb-modeswitch these days, anyway? The comment in
>> the file should point people directly there....

I never ceased work on it and intend to do so for years to come. I would certainly welcome any pointer to the usb_modeswitch main site in the code or the documentation. Although modem developers or engineers should not have a problem finding the site and providing new device information.

>> And, as of now, I would really like to see as many of these devices
>> migrated (albeit slowly) to using usb-modeswitch wherever possible. I
>> know there are a few devices for which that might not be possible, but
>> I am DONE dealing with this same issue over and over and over again.
>> It will certainly be work to migrate support; maybe we should wrap all
>> the relevant unusual_devs.h entires with
>> CONFIG_UPDATED_MODESWITCH_INSTALLED_SO_MAKE_THESE_GO_AWAY during a
>> transition period?

I think it's safe to say that usb_modeswitch is included in all distributions now. Usually, no user interaction is necessary.

> I guess the real problem will be verifying that all of the entries *can*
> go away. This type of hardware tends to get old very fast, but there is
> always someone having a really ancient device.

I will check this and add any missing USB IDs to usb_modeswitch, but I can't shake the feeling that not *all* Huawei entries in "unusual_devs.h" did actually materialize as devices ...

Anyway, as Bjørn said, putting that initialization into the storage driver takes away quite some possibilities to handle these modems in a flexible way.

Josua Dietze