On Tue, 14 Mar 2006, Oliver Neukum wrote: > Am Dienstag, 14. März 2006 22:24 schrieb Alan Stern: > > On Tue, 14 Mar 2006, Alan Stern wrote: > > > > > > > acm_tty_close tty=cd254af8 filp=ce96511c acm=ce24eca0 > > > > > acm_tty_close acm->used=1 acm->dev=00000000 > > > > atm_tty_close called from tty_io.c:release_dev() > > > > acm->used=1 on entry, decrements to zero == final close > > > > acm->dev is NULL (unplugged) so call tty_unregister_device() > > > > > > The disconnect routine shouldn't need to set acm->dev to NULL. The fact > > > that the first disconnect has already occurred can be detected by the fact > > > that acm = usb_get_intfdata(intf) will itself be NULL. > > > > > > Will everything work if you simply delete the line > > > > > > acm->dev = NULL; > > > > > > from acm_disconnect()? > > > > After looking at the code, I see that it won't. The acm_tty_close() > > routine uses acm->dev to tell whether or not the USB device has been > > disconnected. The problem is that when acm->dev is NULL, it calls > > acm_tty_unregister() which requires acm->dev to be non-NULL. > > Maybe I am dense, but what is acm->dev used for in acm_tty_unregister()?
It isn't. I was wrong. Sorry. What Paul needs to track is the refcount for acm->dev. It should be incremented and decremented appropriately -- which means that acm->dev had better not be NULL when acm_tty_unregister runs. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
