Dear Oliver:

> -----Original Message-----
> From: Oliver Neukum [mailto:oneu...@suse.de]
> Sent: Tuesday, March 05, 2013 4:49 PM
> To: Fangxiaozhi (Franko)
> Cc: Bjørn Mork; linux-...@vger.kernel.org; linux-kernel@vger.kernel.org;
> Xueguiying (Zihan); Linlei (Lei Lin); g...@kroah.com; Yili (Neil); Wangyuhua
> (Roger, Credit); Huqiao (C); ba...@ti.com; mdharm-...@one-eyed-alien.net;
> sebast...@breakpoint.cc
> Subject: Re: v3.8 regression: Huawei mode switching fails (was Re: [PATCH
> 2/2]linux-usb:optimize to match the Huawei USB storage devices and support
> new switch command)
> 
> On Tuesday 05 March 2013 02:28:07 Fangxiaozhi wrote:
> 
> Hi,
> 
> >     1. As far as I know, usb_modeswitch is now only integrated in the PC 
> > Linux.
> It isn't integrated to other system with linux kernel, such as Android, Chrome
> OS, etc. On these system, how can we switch the device?
> 
> Then those systems will have to add modeswitch.
> If we are to do mode switching in kernel space, there has to be an additional
> technical benefit over the existing and well working solution in user space.
-----The vendor doesn't want to add the modeswitch on their system. We try to 
push them to do it, but they don't agree.
> 
> >     2. usb_modeswitch often sends the Windows switching command to
> switch Huawei device, but not sends Linux switching command. This maybe
> causes some unexpected problem.
> 
> You have two commands? What is the difference? Anyway, if usb_modeswitch
> has issues, these problems need to be fixed.
------Sorry, it is one command, but with different values in it for different 
system, such as:
        1. For Windows:
        {0x11, 0x06, 0x00, 0x00, 0x00, 0x01, 0x01, 0x00,
-                       0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
        2. For Mac OS: 
        {0x11, 0x06, 0x10, 0x00, 0x00, 0x01, 0x01, 0x00,
-                       0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
        3. For Linux:
        {0x11, 0x06, 0x20, 0x00, 0x00, 0x01, 0x01, 0x00,
-                       0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

        Sometimes, modeswitch will send the command for Windows  to device on 
Linux system, but not the command for Linux. 
> 
> Independent from that, there is a problem with user space mode switching.
> Namely it doesn't work with reset_resume(). Thus we cannot do sane S4 with
> the user space solution.
> However, the problem cannot be solved by merely by adding the switch to the
> storage driver.
-----For this issue, can you offer more details? And we can try to solve it 
together.
> 
>       Regards
>               Oliver

Best Regards,
Franko Fang

Reply via email to