USB: expose Huawei E1550 3G modem
in [Kernel]
|
Prev: Fix inappropriate substraction on tracing_pages_allocated in trace_free_page()in 2.6.27.y series kernel
Next: [PATCH] Drivers: w1: omap_hdq: Fix missing include sched.h
From: Stefan Assmann on 19 Apr 2010 10:20 On 19.04.2010 16:00, Josua Dietze wrote: > Stefan Assmann schrieb: >> The Huawei E1550 3G modem is hidden by default and can be >> exposed by sending some magic initialization code. This >> patch takes care of that. > > This device (as all other Huaweis using this sequence) is > supported by the usb_modeswitch tool which takes of the > switching process. Once installed, no user interaction is > required except plugging. > > Current policy is to leave switching to the userspace if it's > working there. Hi Josua, that's good news. This is part of hardware initialization, so let's move it to the kernel. Or do you know any good reason why the kernel shouldn't handle it? Stefan -- Stefan Assmann | Red Hat GmbH Software Engineer | Otto-Hahn-Strasse 20, 85609 Dornach | HR: Amtsgericht Muenchen HRB 153243 | GF: Brendan Lane, Charlie Peters, sassmann at redhat.com | Michael Cunningham, Charles Cachera -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Josua Dietze on 19 Apr 2010 10:20 Stefan Assmann schrieb: > The Huawei E1550 3G modem is hidden by default and can be > exposed by sending some magic initialization code. This > patch takes care of that. This device (as all other Huaweis using this sequence) is supported by the usb_modeswitch tool which takes of the switching process. Once installed, no user interaction is required except plugging. Current policy is to leave switching to the userspace if it's working there. Josua Dietze -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Matthew Dharm on 19 Apr 2010 10:30 On Mon, Apr 19, 2010 at 04:08:43PM +0200, Stefan Assmann wrote: > On 19.04.2010 16:00, Josua Dietze wrote: > > Stefan Assmann schrieb: > >> The Huawei E1550 3G modem is hidden by default and can be > >> exposed by sending some magic initialization code. This > >> patch takes care of that. > > > > This device (as all other Huaweis using this sequence) is > > supported by the usb_modeswitch tool which takes of the > > switching process. Once installed, no user interaction is > > required except plugging. > > > > Current policy is to leave switching to the userspace if it's > > working there. > > that's good news. This is part of hardware initialization, so let's move > it to the kernel. Or do you know any good reason why the kernel > shouldn't handle it? We've had this discussion, what, over a dozen times already? It keeps coming up every few months. There are two primary reasons to keep this in userspace: 1) Someone might actually want to access the storage mode of these devices. It has come up in the past, and there is no good reason the kernel should deny access to that function of the device by enforcing a switchover. 2) It is much much easier to update a userspace tool than the kernel. Thus, new devices can be supported without a kernel update by end-users. Matt -- Matthew Dharm Home: mdharm-usb(a)one-eyed-alien.net Maintainer, Linux USB Mass Storage Driver Now payink attention, please. This is mouse. Click-click. Easy to use, da? Now you try... -- Pitr to Miranda User Friendly, 10/11/1998
From: Stefan Assmann on 19 Apr 2010 11:10 On 19.04.2010 16:19, Matthew Dharm wrote: > On Mon, Apr 19, 2010 at 04:08:43PM +0200, Stefan Assmann wrote: >> On 19.04.2010 16:00, Josua Dietze wrote: >>> Stefan Assmann schrieb: >>>> The Huawei E1550 3G modem is hidden by default and can be >>>> exposed by sending some magic initialization code. This >>>> patch takes care of that. >>> >>> This device (as all other Huaweis using this sequence) is >>> supported by the usb_modeswitch tool which takes of the >>> switching process. Once installed, no user interaction is >>> required except plugging. >>> >>> Current policy is to leave switching to the userspace if it's >>> working there. >> >> that's good news. This is part of hardware initialization, so let's move >> it to the kernel. Or do you know any good reason why the kernel >> shouldn't handle it? > > We've had this discussion, what, over a dozen times already? It keeps > coming up every few months. > > There are two primary reasons to keep this in userspace: > > 1) Someone might actually want to access the storage mode of these devices. > It has come up in the past, and there is no good reason the kernel should > deny access to that function of the device by enforcing a switchover. You're right about that. For the E1550 it doesn't hide any devices. I'm still able to access the virtual CDROM and the microSD card. Josua, you might know more about that, isn't the hidding of the CDROM/microSD part done separately? > > 2) It is much much easier to update a userspace tool than the kernel. > Thus, new devices can be supported without a kernel update by end-users. Of course. Nobody is talking about removing existing code from any user-space application. Under the condition that no functionality gets lost, wouldn't it be convenient to have the modem exposed by the kernel? If the kernel support doesn't suffice you can still run an updated usb_modeswitch until kernel support is there. This also has the benefit that it would work for people that don't have usb_modeswitch installed. Matt, are you still thinking that is the wrong way of doing it? Stefan -- Stefan Assmann | Red Hat GmbH Software Engineer | Otto-Hahn-Strasse 20, 85609 Dornach | HR: Amtsgericht Muenchen HRB 153243 | GF: Brendan Lane, Charlie Peters, sassmann at redhat.com | Michael Cunningham, Charles Cachera -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Josua Dietze on 19 Apr 2010 11:30
Stefan Assmann schrieb: > You're right about that. For the E1550 it doesn't hide any devices. I'm > still able to access the virtual CDROM and the microSD card. Josua, you > might know more about that, isn't the hidding of the CDROM/microSD part > done separately? This behaviour depends on the respective device. Most devices don't re-expose the installation medium after switching, some do. Anyway, usb_modeswitch is on the road to becoming a standard part of the big distributions, so users won't have to look for it actively. Josua Dietze -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |