For checkpoint/restore we need to know if tty has
exclusive or packet mode set, as well as if pty
is currently locked. Just to be able to restore
this characteristics.
For this sake the following ioctl codes are introduced
- TIOCGPKT to get packet mode state
- TIOCGPTLCK to get Pty locked state
- TIOCGEXCL to get Exclusive mode state
Note this ioctls are a bit unsafe in terms of data
obtained consistency. The tty characteristics might
be changed right after ioctl complete. Keep it in
mind and use this ioctl carefully.
v2:
- Use TIOC prefix for ioctl codes (by jslaby@)
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Pavel Emelyanov <xemul@parallels.com>
CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since this ioctl is for pty devices only move it to pty.c.
v2:
- drop PTY_TYPE_MASTER test since it's master peer
ioctl anyway (by jslaby@)
Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Pavel Emelyanov <xemul@parallels.com>
CC: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently this driver expects the clock-frequency attribute. This
patch allows getting clock-frequency through clk driver API
clk_get_rate() if clock-frequency attribute is not defined.
So in the device bindings for serial device, one can add clocks
phandle to refer to the clk device to get the rate.
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
WARN_RATELIMIT() expects the warning to end with a newline if one
is needed.
Not doing so results in odd looking warnings such as:
[ 1339.454272] tty is NULLPid: 7147, comm: kworker/4:0 Tainted: G W 3.7.0-rc2-next-20121025-sasha-00001-g673f98e-dirty #75
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch make use of del_timer instead of del_timer_sync in the
interrupt context.
The spi_timer function don't use any resources that may release after
running del_timer,
so using the del_timer is also safe and enough in this context.
Signed-off-by: Chen Jun <jun.d.chen@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Tested-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch make use of mod_timer instead of add_timer in the mrdy_assert function.
Because the srdy interrupter can go high when we are running function mrdy_assert and mrdy_assert
can be called by multi-entry. In our medfield platform, spi stress test can encounter this
error logs triggered by the BUG_ON of add_timer function.This patch had been tested on
our medfield platform.
the scenario:
CPU0 CPU1
mrdy_assert
set_bit(IFX_SPI_STATE_TIMER_PENDING)
ifx_spi_handle_srdy
...
clear_bit(IFX_SPI_STATE_TIMER_PENDING)
...
mrdy_assert
set_bit(IFX_SPI_STATE_TIMER_PENDING)
...
add_timer
...
add_timer
Cc: liu chuansheng <chuansheng.liu@intel.com>
Cc: Bi Chao <chao.bi@intel.com>
Signed-off-by: Chen Jun <jun.d.chen@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SPI protocol driver only provide one function (swap_buf()) to swap SPI
data into big endian format, which is only available when SPI
controller's word width is 16 bits. But word width could be configured
as 8/16/32 bits, different word width configure should be mapped to
different swap methods.This patch is to make SPI protocol driver choose
the right swap function corresponding to SPI word width configuration.
cc: liu chuansheng <chuansheng.liu@intel.com>
cc: Chen Jun <jun.d.chen@intel.com>
Signed-off-by: channing <chao.bi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This switches a bunch of allocation and remapping to use the
devm_* garbage collected methods and cleans up the error
path and remove() paths consequently.
devm_ioremap() is only in <linux/io.h> so fix up the
erroneous <asm/*> include as well.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Domenico Andreoli <domenico.andreoli@linux.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the array serial_omap_console_ports is hard coded to 4.
Make it depend on the maximum uart count.
Post to [cfc55bc ARM: OMAP2+: serial: Change MAX_HSUART_PORTS to 6]
the max ports is 6.
Cc: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Special character detect enable if enabled by default.Received data
comparison with XOFF2 data happens by default.
tty provides only XOFF1 no X0FF2 is provided so no need
to enable check for XOFF2.
Keeping this enabled might give some slow transfers due to dummy xoff2
comparison with xoff2 reset value.
Since not all want the XOFF2 support lets not enable it by
default.
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
get_context_loss_count returns an int however it is stored in
unsigned integer context_loss_cnt . This patch tries to make
context_loss_cnt int. So that in case of errors the value
(which may be negative) is not interpreted wrongly.
In serial_omap_runtime_resume in case of errors returned by
get_context_loss_count print a warning and do a restore.
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch converts all static variables of clps711x serial driver
to dynamic allocating. In this case we are should remove console_initcall()
and declare console during driver registration. Early kernel messages can
be retrieved by add "earlyprintk" option to the kernel command line.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Actually, in order to support KGDB over serial console one must
implement two callbacks for character polling. Clone them from
8250 driver with a bit of tuning.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Marko Katic <dromede@gmail.com>
CC: Eric Miao <eric.y.miao@gmail.com>
CC: Russell King <linux@arm.linux.org.uk>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
drivers/tty/serial/pxa.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 55 insertions(+), 0 deletions(-)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The global "normal" spin lock that guards the line discipline
administration is replaced by a raw spin lock. On a PREEMPT_RT system this
prevents unwanted scheduling overhead around the line discipline administration.
On a 200 MHz AT91SAM9261 processor setup this fixes about 100us of scheduling
overhead on a TTY read or write call.
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the missing unlock on the error handling path in function
hvcs_initialize().
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current CE4100 and 8250_pci code have both a limitation preventing the
registration and usage of CE4100's second UART. This patch changes the
platform code fixing up the UART port to work on a relative UART port
base address, as well as the 8250_pci code to make it register 2 UART ports
for CE4100 and pass the port index down to all consumers.
Signed-off-by: Florian Fainelli <ffainelli@freebox.fr>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here I fixed from printk(KERN_ERR, ... to pr_err(... on tty_mutex.c
Signed-off-by: Sangho Yi <antiroot@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vt8500_port is malloced in vt8500_serial_probe() and should be freed
before leaving from the error handling cases, otherwise it will
cause memory leak.
Fix it by move the allocation of vt8500_port after those test.
dpatch engine is used to auto generate this patch.
(https://github.com/weiyj/dpatch)
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This allows us to get rid of the ifdefs in 8250.c.
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modify divisor to select the nearest baud rate divider rather than the
lowest. It minimizes baud rate errors especially on low UART clock
frequencies.
For example, if uartclk is 33000000 and baud is 115200 the ratio is
about 17.9 The current code selects 17 (5% error) but should select 18
(0.5% error).
This 5% error in baud rate leads to garbage on receiving end, while 0.5%
doesn't.
The issue showed up when using the stock 8250 driver for
Synopsys DW UART. This was on a FPGA with ~12MHz UART clock.
When we enabled early serial, we saw garbage which was narrowed down
to the rounding error.
So the bug had been latent and it only showed up with such low clock rates.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare
calls as required by common clock framework.
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a driver has the low_latency flag set and uses the schedule_flip()
function to initiate copying data to the line discipline, a workqueue is
scheduled in but never actually flushed. This is incorrect use of the
low_latency flag (driver should not support the low_latency flag, or use
the tty_flip_buffer_push() function instead). Make sure a warning is
reported to catch incorrect use of the low_latency flag.
This patch goes with: cee4ad1ed9
Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So this is it. The big step why we did all the work over the past
kernel releases. Now everything is prepared, so nothing protects us
from doing that big step.
| | \ \ nnnn/^l | |
| | \ / / | |
| '-,.__ => \/ ,-` => | '-,.__
| O __.´´) ( .` | O __.´´)
~~~ ~~ `` ~~~ ~~
The buffers are now in the tty_port structure and we can start
teaching the buffer helpers (insert char/string, flip etc.) to use
tty_port instead of tty_struct all around.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For that purpose we have to temporarily introduce a second tty back
pointer into tty_port. It is because serial layer, and maybe others,
still do not use tty_port_tty_set/get. So that we cannot set the
tty_port->tty to NULL at will now.
Yes, the fix would be to convert whole serial layer and all its users
to tty_port_tty_set/get. However we are in the process of removing the
need of tty in most of the call sites, so this would lead to a
duplicated work.
Instead we have now tty_port->itty (internal tty) which will be used
only in flush_to_ldisc. For that one it is ensured that itty is valid
wherever the work is run. IOW, the work is synchronously cancelled
before we set itty to NULL and also before hangup is processed.
After we need only tty_port and not tty_struct in most code, this
shall be changed to tty_port_tty_set/get and itty removed completely.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During the move of tty buffers from tty_struct to tty_port, we will
need to switch all users of buf to tty->port->buf. There are many
functions where this is accessed directly in their code many times.
Cache the tty->buf pointer in such functions now and change only
single lines in each function in the next patch.
Not that it is convenient for the next patch, but the code is now also
more readable.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
They are only TTY buffers specific. And the buffers will go to
tty_port in the next patches. So to remove the need to have both
tty_port and tty_struct at some places, let us move the flags to
tty_port.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In some funtions we need only n_tty_data, so pass it down directly in
case tty is not needed there.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
atomic_write_lock is not n_tty specific, so move it up in the
tty_struct.
And since these are the last ones to move, remove also the comment
saying there are some ldisc' members. There are none now.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All the ring-buffers...
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here we move bitmaps and use DECLARE_BITMAP to declare them in the new
structure. And instead of memset, we use bitmap_zero as it is more
appropriate.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here we start moving all the n_tty related bits from tty_struct to
the newly defined n_tty_data struct in n_tty proper.
In this patch primitive members and bits are moved. The rest will be
done per-partes in the next patches.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All n_tty related members from tty_struct will be moved here.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a private member of n_tty. Stop accessing it. Instead, take is
as an argument.
This is needed to allow clean switch of the private members to a
separate private structure of n_tty.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* BUG_ON(!tty) in n_tty_set_termios -- it cannot be called with tty ==
NULL. It is called from two call sites. First, from n_tty_open where
we have a valid tty. Second, as ld->ops->set_termios from
tty_set_termios. But there we have a valid tty too.
* if (!tty) in n_tty_open -- why would the TTY layer call ldisc's
open with an invalid TTY? No it indeed does not. All call sites have
a tty and dereference that.
* BUG_ON(!tty->read_buf) in n_tty_read -- this used to be a valid
check. The ldisc handling was broken some time ago when I added the
check to ensure everything is OK. It still can catch the case, but
no later than we move the buffer to ldisc data. Then there will be
no read_buf in tty_struct, i.e. nothing to check for.
* if (!tty->read_buf) in n_tty_receive_buf -- this should never
happen. All callers of ldisc->ops->receive_ops should hold a
reference to an ldisc and close (which frees read_buf) cannot be
called until the reference is dropped.
* if (WARN_ON(!tty->read_buf)) in n_tty_read -- the same as in the
previous case.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ldisc->open and close are called only once and cannot cross. So the
tests in open and close are superfluous. Remove them. (But leave sets
to NULL to ensure there is not a bug somewhere.)
And when the tests are gone, handle properly failures in open. We
leaked read_buf if allocation of echo_buf failed before. Now this is
not the case anymore.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We reintroduced tty_ldisc_wait_idle in 100eeae2c5 (TTY: restore
tty_ldisc_wait_idle) and used in set_ldisc. Then we added it also to
the hangup path in 92f6fa09bd (TTY: ldisc, do not close until there
are readers). And we noted that there is one more path:
~ Before 65b770468e tty_ldisc_wait_idle was called also from
~ tty_ldisc_release. It is called from tty_release, so I don't think
~ we need to restore that one.
Well, I was wrong. There might still be holders of an ldisc
reference. Not from userspace, but drivers. If they take a reference
and a user closes the device immediately after that, we have a
problem. ldisc is halted and closed by TTY, but the driver still may
call some ldisc's operation and cause a crash.
So restore the tty_ldisc_wait_idle call also to the third location
where it was before 65b770468e (tty-ldisc: turn ldisc user count
into a proper refcount). Now we should be safe with respect to the
ldisc reference counting as all* tty_ldisc_close paths are safely
called with reference count of one.
* Not the one in tty_ldisc_setup's fail path. But that is called
before the first open finishes. So userspace does not see it yet.
Even thought the driver is given the TTY already via ->install, it
should not take a reference to the ldisc yet. If some driver is to
do this, we should put one tty_ldisc_wait_idle also in the setup.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There used to be a single tty_ldisc_ref_wait. But then, when a
big-tty-mutex (BTM) was introduced, it has to be tty_ldisc_ref +
tty_unlock + tty_ldisc_ref_wait + tty_lock. Later, BTM was removed
from that path and tty_ldisc_ref + tty_ldisc_ref_wait remained there.
But it makes no sense now. So leave there only tty_ldisc_ref_wait.
And when we have a reference to an ldisc, actually use it in the loop.
Otherwise it may be racy.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we have control over tty->driver_data in pty, we can just
kill the /dev/pts/ in pty code too. Namely, in ->shutdown hook of
tty. For pty, this is called only once, for whichever end is closed
last. But we don't care, both driver_data are the inode as it used to
be till now.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
