lkml.org 
[lkml]   [2011]   [Nov]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: tty related lockdep trace during bootup on 3.2-rc2
From
On Wed, Nov 23, 2011 at 2:12 AM, Jiri Slaby <jslaby@suse.cz> wrote:
> Oh, how it can be? You should vhangup the device on disconnect. Then you
> will be sure all close calls were performed before freeing the port.
> Then you can free the port, right?
>
> Like:
> * forbid further opens
> * tty_vhangup
> * stop the device
> * free the device state

Ok, interesting. It seems pretty different from what the driver is
currently doing. I'll see if I can figure out how to rework the
disconnect code.

I guess one remaining concern is that someone might still hold the
device open after hangup, so if we free the device state, which
includes the tty_port, something bad might happen, no?

> Also it looks like you have a leak in disconnect when there are users
> still. If I am looking correctly?

Funny you should say that. I'm also trying to investigate a case in
which the driver appears to leak tty devices, i.e. after a few days of
stress testing, /sys/class/tty is full of dangling ttyACMx symlinks
and new devices are ignored because acm_table is full.

Havard


\
 
 \ /
  Last update: 2011-11-23 19:01    [W:0.151 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site