Re: usb+sysfs: duplicate filename 'bInterfaceNumber'

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

On Tue, Oct 16, 2007 at 02:04:43PM -0400, Alan Stern wrote:
> On Tue, 16 Oct 2007, Matthew Dharm wrote:
> > I haven't looked at this code at all, but neither approach feels right to
> > me.
> > 
> > How does this work at all?  Even if you load a driver later, wouldn't it
> > call usb_set_interface(), which would call usb_create_sysfs_intf_files()
> > and hit the same issue?
> usb_set_interface() is smart enough to remove the old interface files
> before creating new ones, since it expects them to exist already.  
> Hence there's no problem in that scenario.
> But usb_set_configuration doesn't expect there to be any pre-existing
> interface files, because there isn't even an interface until the
> registration is performed.

And I'm guessing that you can't call usb_create_sysfs_intf_files() until
registration is performed, right?

> The most important reason has to do with the endpoint pseudo-devices.  
> Different altsettings can have different endpoints, so those have to be
> removed and re-created whenever the altsetting changes.

Right, altsettings.  I forgot about those.  I only ever think in terms of
multiple configurations.


If usb_set_interface() has to be smart enough to remove existing files
first already, then I guess it's reasonably symmetric to have
usb_set_configuration() have the same smarts.  Maybe they can share some
common code, even.


Matthew Dharm                              Home: mdharm-usb@xxxxxxxxxxxxxxxxxx 
Maintainer, Linux USB Mass Storage Driver

C:  Why are you upgrading to NT?
AJ: It must be the sick, sadistic streak that runs through me.
					-- Chief and A.J.
User Friendly, 5/12/1998

Attachment: pgpTogyWeT69r.pgp
Description: PGP signature

This email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >>
To unsubscribe, use the last form field at:

[Home]     [Video for Linux]     [Photo]     [Yosemite Forum]     [Yosemite Photos]    [Video Projectors]     [PDAs]     [Hacking TiVo]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Devices]     [Big List of Linux Books]     [Free Dating]

  Powered by Linux