On 10/17/07, Alan Stern <[EMAIL PROTECTED]> wrote: > On Tue, 16 Oct 2007, Matthew Dharm wrote: > > > 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? > > 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. > > > > *grumble* > > > > 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. > > It's not a big deal to remove the files first. In fact, here's a patch > to do it. Dave, see if this doesn't fix your problem. I don't like it > much because it does an unnecessary remove/create cycle, but that's > better than doing something wrong.
Although it's not the best fix, the problem is fixed, Thanks. > > It's slightly odd that the sysfs core logs an error when you try to > create the same file twice but it doesn't when you try to remove a > non-existent file (or try to remove an existing file twice). Oh > well... > > Alan Stern > > > > Index: usb-2.6/drivers/usb/core/message.c > =================================================================== > --- usb-2.6.orig/drivers/usb/core/message.c > +++ usb-2.6/drivers/usb/core/message.c > @@ -1643,7 +1643,13 @@ free_interfaces: > intf->dev.bus_id, ret); > continue; > } > - usb_create_sysfs_intf_files (intf); > + > + /* The driver's probe method can call usb_set_interface(), > + * which would mean the interface's sysfs files are already > + * created. Just in case, we'll remove them first. > + */ > + usb_remove_sysfs_intf_files(intf); > + usb_create_sysfs_intf_files(intf); > } > > usb_autosuspend_device(dev); > > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/