Hi, On Thu, Nov 06, 2014 at 10:08:55AM +0100, Krzysztof Opasiak wrote: > > From: Felipe Balbi [mailto:balbi@xxxxxx] > > Sent: Wednesday, November 05, 2014 8:43 PM > > To: Krzysztof Opasiak > > Cc: balbi@xxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; > > bigeasy@xxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; > > s.wadas@xxxxxxxxxxx; k.lewandowsk@xxxxxxxxxxx; > > andrzej.p@xxxxxxxxxxx; m.szyprowski@xxxxxxxxxxx > > Subject: Re: [RFC PATCH] usb: gadget: composite: Provide list of > > registered functions > > > > On Mon, Oct 20, 2014 at 01:41:37PM +0200, Krzysztof Opasiak wrote: > > > Driver which provides implementation of some USB functions > > registers > > > its usb_function_driver structure in framework. > > > Function drivers are identifed using registered name. > > > > > > When gadget is composed user must know what names has been > > > > "user *must" know", why ? > > Because he has to create directory with suitable name. This means that > he needs to know that Mass storage module has been registered as > mass_storage, and that gadget zero provides functions registered as > Loopback and SourceSink. > > Let's say that you got system and kernel image. You may use uname -r to > learn about kernel version, let's say that it is 3.17. You may also > check what kernel modules has been provided with image. But how to learn > which usb function has been build into kernel? > > I see some analogy to filesystems. When you would like to use -t option > in mount you have to know how Ext4 or Function FS has been registered in > fs framework. Kernel allows you to learn about all loaded or build-in > modules. You may simply do this using /proc/filesystems where you will > get all fs names registered in kernel. So in a few steps: that's a good analogy and you're starting to convince me of the need for this interface. > 1. I have some disk image with Ext4. I would like to know if I have > support for this fs type in my kernel and what name should I use to -t > option. > 2. I check my kernel modules but Ext4 not found > 3. cat /proc/filesystems and I see that yes there is Ext4 and it has > been compiled-in my kernel and it has been registered as "ext4" > 4. Now I have gather all information and I may simply mount -t ext4 ... > > Don't you think that such scenario should be also doable with usb > functions? > > User ends up in empty functions dir of some gadget and what now? How to > allow him to ask kernel what is available? How to learn what functions > has been build-in and what names has been registered in framework? (ocf > kernel config but it's not always available) right, makes sense to me. Care to respin the patch ? -- balbi
Attachment:
signature.asc
Description: Digital signature
