Re: [RFC PATCH] USB: remove CONFIG_USB_DEVICEFS

From: Jeff Chua
Date: Fri May 25 2012 - 03:06:30 EST


On Fri, May 25, 2012 at 2:01 PM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, May 25, 2012 at 01:48:06PM +0800, Jeff Chua wrote:
>> On Fri, May 25, 2012 at 5:52 AM, Greg Kroah-Hartman
>> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>> > On Thu, May 24, 2012 at 11:55:16PM +0800, Jeff Chua wrote:
>> >> On Thu, Apr 26, 2012 at 11:12 PM, Greg Kroah-Hartman
>> >> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>> >> > On Thu, Apr 26, 2012 at 11:06:45AM -0400, Alan Stern wrote:
>> >> >> On Wed, 25 Apr 2012, Greg Kroah-Hartman wrote:
>> >> >>
>> >> >> > This option has been deprecated for many years now, and no userspace
>> >> >> > tools use it anymore, so it should be safe to finally remove it.
>> >> >> >
>> >> >> > Reported-by: Kay Sievers <kay@xxxxxxxx>
>> >> >> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>> >> >> >
>> >> >> > Anyone object to me queuing this up for the 3.5 kernel release?
>> >> >>
>> >> >> I'm not sure about this.  There are a few systems still floating around
>> >> >> that don't use udev; on those systems /proc/bus/usb is the only way for
>> >> >> user programs to control USB devices.  Admittedly, I have no idea
>> >> >> whether any such systems will be using 3.5 or later kernels...
>> >> >
>> >> > They don't have to use udev, they can use devtmpfs (which is what the
>> >> > majority of embedded systems use today), or they can just use static
>> >> > device nodes to get access to these devices, the char node is still
>> >> > present, we aren't getting rid of them at all.
>> >>
>> >> Looks like vmware is breaking. Can't find any usb devices. I'm not using udev.
>> >
>> > vmware doesn't use usbfs, otherwise how would it be working on all of
>> > the systems out there that haven't mounted usbfs for years?
>> >
>> > What exactly broke?  What version of vmware are you using, and is the
>> > problem in the guest or host?
>> >
>> > We delayed other usbfs changes for years due to vmware "issues", it
>> > wouldn't be the first time we've had to handle this :(
>>
>>
>> VMWare workstation 8.0.3
>>
>> # vmware-usbarbitrator -f --info
>> DICT       product.buildNumber = 703057
>> DICT           product.version = 8.0.3
>> DICT workstation.product.version = 8.0.3
>> DICT              product.name = VMware Workstation
>> VMware USB Arbitration Service Version 8.4.19
>> USB: Unable to open "/proc/bus/usb/devices" (No such file or directory).
>> No USB enumerator!
> Ok, I have no idea what any of this means.

I think the process "vmware-usbarbitrator" is trying to read
proc/bus/usb/devices and can't find the file, so when I go to vmware,
it can't find any usb devices.


> What host os are you using that does not have udev in it?

No udev. My own vanilla kernel.


> What client os are you using that wants access to the USB ports that is
> not working?  Is this the latest version of vmware (hint, I have no idea
> what their version numbering is, you are going to have to look that up,
> but I know they have fixed stuff like this in their newer releases.)

It's the latest vmware workstation 8.0.3. The vmware "Removable
Devices" tab is not showing any USB devices.

> What release of the host os are you running?

Linux-3.4.0 with commit 07acfc2a9349a8ce45b236c2624dad452001966b.

> If you aren't using udev, what are you using for your static device nodes?

Usually, with /proc/bus/usb/devices present, vmware will just read
from this file and I get to see the usb devices in vmware.

> If you are using static device nodes, why don't you have the /dev/usb/
> nodes on your system (i.e. why didn't your distro create them for you?)

Didn't check that as it was working just few days earlier:)

>> If I revert back to git pull 3 years earlier, it works.
> A git pull of a 3 year old kernel?  What are you talking about here?

It should have been 3 days ago. Sorry! 3 linux days seems like 3 years
in the human time:)


Thanks,
Jeff
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