user/sven/linux.git/include/linux/tty_driver.h, branch v3.2.45

TTY: pty, fix pty counting

2011-08-23T17:10:38Z

tty_operations->remove is normally called like: queue_release_one_tty ->tty_shutdown ->tty_driver_remove_tty ->tty_operations->remove However tty_shutdown() is called from queue_release_one_tty() only if tty_operations->shutdown is NULL. But for pty, it is not. pty_unix98_shutdown() is used there as ->shutdown. So tty_operations->remove of pty (i.e. pty_unix98_remove()) is never called. This results in invalid pty_count. I.e. what can be seen in /proc/sys/kernel/pty/nr. I see this was already reported at: https://lkml.org/lkml/2009/11/5/370 But it was not fixed since then. This patch is kind of a hackish way. The problem lies in ->install. We allocate there another tty (so-called tty->link). So ->install is called once, but ->remove twice, for both tty and tty->link. The fix here is to count both tty and tty->link and divide the count by 2 for user. And to have ->remove called, let's make tty_driver_remove_tty() global and call that from pty_unix98_shutdown() (tty_operations->shutdown). While at it, let's document that when ->shutdown is defined, tty_shutdown() is not called. Signed-off-by: Jiri Slaby Cc: Alan Cox Cc: "H. Peter Anvin" Cc: stable Signed-off-by: Greg Kroah-Hartman

tty: now phase out the ioctl file pointer for good

2011-02-17T19:59:56Z

Only oddities here are a couple of drivers that bogusly called the ldisc helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes away. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

tiocmset: kill the file pointer argument

2011-02-17T19:52:43Z

Doing tiocmget was such fun we should do tiocmset as well for the same reasons Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

tiocmget: kill off the passing of the struct file

2011-02-17T19:47:33Z

We don't actually need this and it causes problems for internal use of this functionality. Currently there is a single use of the FILE * pointer. That is the serial core which uses it to check tty_hung_up_p. However if that is true then IO_ERROR is also already set so the check may be removed. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

tty: fix typos/errors in tty_driver.h comments

2010-12-16T21:14:32Z

Fix various typos and other errors in comments of tty_driver.h. The most significant is the wrong name of a function for the description of TTY_DRIVER_DYNAMIC_DEV. Signed-off-by: Timur Tabi Signed-off-by: Greg Kroah-Hartman

TTY: include termios.h in tty_driver.h

2010-11-16T20:50:17Z

We reference termios and termiox in tty_driver.h, but we do not include linux/termios.h where these are defined. Add the #include properly. Otherwise when we include tty_driver.h, we get compile errors. Signed-off-by: Jiri Slaby Cc: Alan Cox Cc: Greg KH Signed-off-by: Greg Kroah-Hartman

tty: Make tiocgicount a handler

2010-10-22T17:20:04Z

Dan Rosenberg noted that various drivers return the struct with uncleared fields. Instead of spending forever trying to stomp all the drivers that get it wrong (and every new driver) do the job in one place. This first patch adds the needed operations and hooks them up, including the needed USB midlayer and serial core plumbing. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

tty: Fix regressions caused by commit b50989dc

2009-09-27T20:35:16Z

The following commit made console open fails while booting: commit b50989dc444599c8b21edc23536fc305f4e9b7d5 Author: Alan Cox Date: Sat Sep 19 13:13:22 2009 -0700 tty: make the kref destructor occur asynchronously Due to tty release routines run in a workqueue now, error like the following will be reported while booting: INIT open /dev/console Input/output error It also causes hibernation regression to appear as reported at http://bugzilla.kernel.org/show_bug.cgi?id=14229 The reason is that now there's latency issue with closing, but when we open a "closing not finished" tty, -EIO will be returned. Fix it as per the following Alan's suggestion: Fun but it's actually not a bug and the fix is wrong in itself as the port may be closing but not yet being destructed, in which case it seems to do the wrong thing. Opening a tty that is closing (and could be closing for long periods) is supposed to return -EIO. I suspect a better way to deal with this and keep the old console timing is to split tty->shutdown into two functions. tty->shutdown() - called synchronously just before we dump the tty onto the waitqueue for destruction tty->cleanup() - called when the destructor runs. We would then do the shutdown part which can occur in IRQ context fine, before queueing the rest of the release (from tty->magic = 0 ... the end) to occur asynchronously The USB update in -next would then need a call like if (tty->cleanup) tty->cleanup(tty); at the top of the async function and the USB shutdown to be split between shutdown and cleanup as the USB resource cleanup and final tidy cannot occur synchronously as it needs to sleep. In other words the logic becomes final kref put make object unfindable async clean it up Signed-off-by: Dave Young [ rjw: Rebased on top of 2.6.31-git, reworked the changelog. ] Signed-off-by: "Rafael J. Wysocki" [ Changed serial naming to match new rules, dropped tty_shutdown as per comments from Alan Stern - Linus ] Signed-off-by: Linus Torvalds

tty: throttling race fix

2009-06-11T15:50:59Z

The tty throttling code can race due to the lock drops. It takes very high loads but this has been observed and verified by Rob Duncan. The basic problem is that on an SMP box we can go CPU #1 CPU #2 need to throttle ? suppose we should buffer space cleared are we throttled yes ? - unthrottle call throttle method This changeet take the termios lock to protect against this. The termios lock isn't the initial obvious candidate but many implementations of throttle methods already need to poke around their own termios structures (and nobody really locks them against a racing change of flow control). This does mean that anyone who is setting tty->low_latency = 1 and then calling tty_flip_buffer_push from their unthrottle method is going to end up collapsing in a pile of locks. However we've removed all the known bogus users of low_latency = 1 and such use isn't safe anyway for other reasons so catching it would be an improvement. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds

tty: Correct inline types for tty_driver_kref_get()

2009-04-07T15:44:04Z

tty_driver_kref_get() should be static inline and not extern inline (the latter even changed it's semantics in gcc >= 4.3). Signed-off-by: Adrian Bunk Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds