Fwd: Information request on /dev/bus/usb

Fwd: Information request on /dev/bus/usb

[Ahamed]

I hope you are well and doing great.

I really want some help from you regarding the /dev/bus/usb


Initially, we were on 3.4 Kernel and were using usbfs. Hence, using
the command "mount -t usbfs none /proc/bus/usb". This showed all our
usb devices under /proc/bus/usb.

Now we have moved to 3.14 and I understand that usbfs is no longer supported.

But I am not able to see the devices under /dev/bus/usb. I see them
under /sys/bus/usb. I came to know that /dev is managed by udev. lsusb
is not working since there is nothing under /dev/bus/usb.

Can you help in giving some hints on how to resolve this issue?

Thanks in advance for the help.

regards,
Ahamed

Re: Fwd: Information request on /dev/bus/usb

[Greg KH]

On Wed, Feb 10, 2016 at 01:04:57AM +0530, Ahamed wrote:
> I hope you are well and doing great.
> 
> I really want some help from you regarding the /dev/bus/usb
> 
> 
> Initially, we were on 3.4 Kernel and were using usbfs. Hence, using
> the command "mount -t usbfs none /proc/bus/usb". This showed all our
> usb devices under /proc/bus/usb.
> 
> Now we have moved to 3.14 and I understand that usbfs is no longer supported.
> 
> But I am not able to see the devices under /dev/bus/usb.

They should still be there, perhaps your distro did not properly update
other things needed for this?

> I see them
> under /sys/bus/usb. I came to know that /dev is managed by udev.

And devtmpfs, which you do have enabled, right?

> lsusb
> is not working since there is nothing under /dev/bus/usb.

Then you should update your version of libusb and usbutils, it handled
this change automatically.

And note, 3.14 is very old and obsolete, I suggest updating to a more
modern kernel version, or, ask these questions to the company that is
forcing you to stay with such an old and obsolete kernel version, as you
are paying them for support.

Hope this helps,

greg k-h

Re: Fwd: Information request on /dev/bus/usb

[Ahamed]

Dear Greg,

> And devtmpfs, which you do have enabled, right?

Yes, devtmps is enabled

>> lsusb
>> is not working since there is nothing under /dev/bus/usb.

>Then you should update your version of libusb and usbutils, it handled
>this change automatically.

Yes, I am trying to update these libs.


>They should still be there, perhaps your distro did not properly update
>other things needed for this?
I am trying to find out why the devices are not showing under /dev/bus/usb.
I dont even find the folder  bus inside /dev. Can you please let me
know if there are any configuration that is needed?
Also, i dont see udev daemon running on the box.

regards,
Ahamed

On Wed, Feb 10, 2016 at 1:21 AM, Greg KH <greg@kroah.com> wrote:
> On Wed, Feb 10, 2016 at 01:04:57AM +0530, Ahamed wrote:
>> I hope you are well and doing great.
>>
>> I really want some help from you regarding the /dev/bus/usb
>>
>>
>> Initially, we were on 3.4 Kernel and were using usbfs. Hence, using
>> the command "mount -t usbfs none /proc/bus/usb". This showed all our
>> usb devices under /proc/bus/usb.
>>
>> Now we have moved to 3.14 and I understand that usbfs is no longer supported.
>>
>> But I am not able to see the devices under /dev/bus/usb.
>
> They should still be there, perhaps your distro did not properly update
> other things needed for this?
>
>> I see them
>> under /sys/bus/usb. I came to know that /dev is managed by udev.
>
> And devtmpfs, which you do have enabled, right?
>
>> lsusb
>> is not working since there is nothing under /dev/bus/usb.
>
> Then you should update your version of libusb and usbutils, it handled
> this change automatically.
>
> And note, 3.14 is very old and obsolete, I suggest updating to a more
> modern kernel version, or, ask these questions to the company that is
> forcing you to stay with such an old and obsolete kernel version, as you
> are paying them for support.
>
> Hope this helps,
>
> greg k-h

Re: Fwd: Information request on /dev/bus/usb

[Greg KH]

On Wed, Feb 10, 2016 at 01:48:40AM +0530, Ahamed wrote:
> Dear Greg,
> 
> > And devtmpfs, which you do have enabled, right?
> 
> Yes, devtmps is enabled
> 
> >> lsusb
> >> is not working since there is nothing under /dev/bus/usb.
> 
> >Then you should update your version of libusb and usbutils, it handled
> >this change automatically.
> 
> Yes, I am trying to update these libs.
> 
> 
> >They should still be there, perhaps your distro did not properly update
> >other things needed for this?
> I am trying to find out why the devices are not showing under /dev/bus/usb.
> I dont even find the folder  bus inside /dev. Can you please let me
> know if there are any configuration that is needed?
> Also, i dont see udev daemon running on the box.

Then I suggest you work on fixing that first :)

Also, please talk to the distro developers who put together your system,
odds are there are lots of things you should be upgrading at the same
time you upgrade your kernel version.

good luck!

greg k-h

Re: Fwd: Information request on /dev/bus/usb

[Ahamed]

Hi,

Looks like we have some issues enabling udev.
So, as an alternative, I mounted devtmpfs using the command

mount -t devtmpfs none /dev

Now all the USB devices are available.

Thank you for the help.

regards,
Ahamed

On Wed, Feb 10, 2016 at 2:31 AM, Greg KH <greg@kroah.com> wrote:
> On Wed, Feb 10, 2016 at 01:48:40AM +0530, Ahamed wrote:
>> Dear Greg,
>>
>> > And devtmpfs, which you do have enabled, right?
>>
>> Yes, devtmps is enabled
>>
>> >> lsusb
>> >> is not working since there is nothing under /dev/bus/usb.
>>
>> >Then you should update your version of libusb and usbutils, it handled
>> >this change automatically.
>>
>> Yes, I am trying to update these libs.
>>
>>
>> >They should still be there, perhaps your distro did not properly update
>> >other things needed for this?
>> I am trying to find out why the devices are not showing under /dev/bus/usb.
>> I dont even find the folder  bus inside /dev. Can you please let me
>> know if there are any configuration that is needed?
>> Also, i dont see udev daemon running on the box.
>
> Then I suggest you work on fixing that first :)
>
> Also, please talk to the distro developers who put together your system,
> odds are there are lots of things you should be upgrading at the same
> time you upgrade your kernel version.
>
> good luck!
>
> greg k-h

Re: Fwd: Information request on /dev/bus/usb

[Greg KH]

On Wed, Feb 10, 2016 at 04:48:49PM +0530, Ahamed wrote:
> Hi,
> 
> Looks like we have some issues enabling udev.
> So, as an alternative, I mounted devtmpfs using the command
> 
> mount -t devtmpfs none /dev
> 
> Now all the USB devices are available.

udev is not an "alternative" to devtmpfs, they work in tandom, you need
both.

good luck!

greg k-h