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2011-07-25Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6Linus Torvalds1-1/+1
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (26 commits) amba pl011: workaround for uart registers lockup n_gsm: fix the wrong FCS handling pch_uart: add missing comment about OKI ML7223 pch_uart: Add MSI support tty: fix "IRQ45: nobody cared" PTI feature to allow user to name and mark masterchannel request. 0 for o PTI Makefile bug. tty: serial: samsung.c remove legacy PM code. SERIAL: SC26xx: Fix link error. serial: mrst_max3110: initialize waitqueue earlier mrst_max3110: Change max missing message priority. tty: s5pv210: Add delay loop on fifo reset function for UART tty/serial: Fix XSCALE serial ports, e.g. ce4100 serial: bfin_5xx: fix off-by-one with resource size drivers/tty: use printk_ratelimited() instead of printk_ratelimit() tty: n_gsm: Added refcount usage to gsm_mux and gsm_dlci structs tty: n_gsm: Add raw-ip support tty: n_gsm: expose gsmtty device nodes at ldisc open time pch_phub: Fix register miss-setting issue serial: 8250, increase PASS_LIMIT ...
2011-07-01tty: fix "IRQ45: nobody cared"Andrew McGregor1-1/+1
Unthrottling the TTY during close ends up enabling interrupts on a device not on the active list, which will never have the interrupts cleared. Doctor, it hurts when I do this. >>> On 6/2/2011 at 01:56 AM, in message <20110601145608.3e586e16@bob.linux.org.uk>, Alan Cox <alan@linux.intel.com> wrote: > On Wed, 01 Jun 2011 10:34:07 +1200 > "andrew mcgregor" <andrew.mcgregor@alliedtelesis.co.nz> wrote: > > The LKML message > > http://kerneltrap.org/mailarchive/linux-kernel/2010/2/25/4541847 from > > February doesn't seem to have been resolved since. We struck the > > issue, and the patch below (against 2.6.32) fixes it. Should I > > supply a patch against 3.0.0rc? > > I think that would be sensible. I don't actually see how you hit it as > the IRQ ought to be masked by then but it's certainly wrong for n_tty > to be calling into check_unthrottle at that point. > > So yes please send a patch with a suitable Signed-off-by: line to > linux-serial and cc GregKH <greg@kroah.com> as well. > > Alan Signed-off-by: Andrew McGregor <andrew.mcgregor@alliedtelesis.co.nz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-07TTY: ntty, add one more sanity checkJiri Slaby1-0/+1
With the previous patch, we fixed another bug where read_buf was freed while we still was in n_tty_read. We currently check whether read_buf is NULL at the start of the function. Add one more check after we wake up from waiting for input. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-06-04Revert "tty: make receive_buf() return the amout of bytes received"Linus Torvalds1-14/+47
This reverts commit b1c43f82c5aa265442f82dba31ce985ebb7aa71c. It was broken in so many ways, and results in random odd pty issues. It re-introduced the buggy schedule_work() in flush_to_ldisc() that can cause endless work-loops (see commit a5660b41af6a: "tty: fix endless work loop when the buffer fills up"). It also used an "unsigned int" return value fo the ->receive_buf() function, but then made multiple functions return a negative error code, and didn't actually check for the error in the caller. And it didn't actually work at all. BenH bisected down odd tty behavior to it: "It looks like the patch is causing some major malfunctions of the X server for me, possibly related to PTYs. For example, cat'ing a large file in a gnome terminal hangs the kernel for -minutes- in a loop of what looks like flush_to_ldisc/workqueue code, (some ftrace data in the quoted bits further down). ... Some more data: It -looks- like what happens is that the flush_to_ldisc work queue entry constantly re-queues itself (because the PTY is full ?) and the workqueue thread will basically loop forver calling it without ever scheduling, thus starving the consumer process that could have emptied the PTY." which is pretty much exactly the problem we fixed in a5660b41af6a. Milton Miller pointed out the 'unsigned int' issue. Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reported-by: Milton Miller <miltonm@bga.com> Cc: Stefan Bigler <stefan.bigler@keymile.com> Cc: Toby Gray <toby.gray@realvnc.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-22tty: make receive_buf() return the amout of bytes receivedFelipe Balbi1-47/+14
it makes it simpler to keep track of the amount of bytes received and simplifies how flush_to_ldisc counts the remaining bytes. It also fixes a bug of lost bytes on n_tty when flushing too many bytes via the USB serial gadget driver. Tested-by: Stefan Bigler <stefan.bigler@keymile.com> Tested-by: Toby Gray <toby.gray@realvnc.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-04tty: fix endless work loop when the buffer fills upLinus Torvalds1-0/+6
Commit f23eb2b2b285 ('tty: stop using "delayed_work" in the tty layer') ended up causing hung machines on UP with no preemption, because the work routine to flip the buffer data to the ldisc would endlessly re-arm itself if the destination buffer had filled up. With the delayed work, that only caused a timer-driving polling of the tty state every timer tick, but without the delay we just ended up with basically a busy loop instead. Stop the insane polling, and instead make the code that opens up the receive room re-schedule the buffer flip work. That's what we should have been doing anyway. This same "poll for tty room" issue is almost certainly also the cause of excessive kworker activity when idle reported by Dave Jones, who also reported "flush_to_ldisc executing 2500 times a second" back in Nov 2010: http://lkml.org/lkml/2010/11/30/592 which is that silly flushing done every timer tick. Wasting both power and CPU for no good reason. Reported-and-tested-by: Alexander Beregalov <a.beregalov@gmail.com> Reported-and-tested-by: Sitsofe Wheeler <sitsofe@yahoo.com> Cc: Greg KH <gregkh@suse.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05TTY: create drivers/tty and move the tty core files thereGreg Kroah-Hartman1-0/+2121
The tty code should be in its own subdirectory and not in the char driver with all of the cruft that is currently there. Based on work done by Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>