n_gsm use a simple approach: every writing to fifo correspond exactly one
reading from fifo. There are no problem in this approach until we read
less bytes then we write. As result fifo may owerflow. This leads to packet
loss and very slow responce.
For example, this happens with ping packets (about 96 byte each) and default
gsm->mtu = 64. As result we get 50 sec ping timeout and 20% packet loss.
Fix the problem by reading and sending all data from the fifo
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
in adaption=2 case we should put 1 or 2 byte with modem status bits
at the beginning of a buffer pointed by "dp". n_gsm use 1 byte case,
so it allocate a buffer of len + 1 size. As result we should:
* put 1 byte of modem status bits
* increase data pointer
* put "len" bytes of data
but actually we have:
* increase first byte with the value of modem status bits
* decrease "len"
* put orig_len - 1 bytes of data starting from the buffer beggining
This is evidently wrong.
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A DISC on DLCI 0 should close down the mux but Michael Lauer reports this
is not the case for some modems. Send a CLD as well.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Tested-by: Michael Lauer
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* '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
...
FCS could be GSM0_SOF, so will break state machine...
[This byte isn't quoted in any way so a SOF here doesn't imply an error
occurred.]
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org> [3.0]
[Trivial but best backported once its in 3.1rc I think]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The gsm_mux is created/destroyed when ldisc is
opened/closed but clients of the MUX channel devices (gsmttyN)
may access this structure as long as the TTYs are open.
For the open, the ldisc open is guaranteed to preceed the TTY open,
but the close has no such guaranteed ordering. As a result,
the gsm_mux can be freed in the ldisc close before being accessed
by one of the TTY clients. This can happen if the ldisc is removed
while there are open, active MUX channels.
A similar situation exists for DLCI-0, it is basically a resource
shared by MUX and DLCI , and should not be freed while they can
be accessed
To avoid this, gsm_mux and dlcis now have a reference counter
ldisc open takes a reference on the mux and all the dlcis
gsmtty_open takes a reference on the mux, dlci0 and its specific
dlci. Dropping the last reference initiates the actual free.
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds the ability to open a network data connection over a mux
virtual tty channel. This is for modems that support data connections
with raw IP frames instead of PPP. On high speed data connections this
eliminates a significant amount of PPP overhead. To use this interface,
the application must first tell the modem to open a network connection on
a virtual tty. Once that has been accomplished, the app will issue an
IOCTL on that virtual tty to create the network interface. The IOCTL will
return the index of the interface created.
The two IOCTL commands are:
ioctl( fd, GSMIOC_ENABLE_NET );
ioctl( fd, GSMIOC_DISABLE_NET );
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The n_gsm driver being an ldisc, does not provide a convenient method
e.g. udev to create the tty device nodes automatically when the ldisc
is opened.
The TTY device nodes are now created via calls to tty_register_device
from the ldisc open.
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
gsm_dlci_data_output_framed() was doing:
memcpy(dp, skb_pull(dlci->skb, len), len);
The problem is skb_pull() returns the post-increment data ptr
so the first chunk of dlci->skb->data is leaked.
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The modem status can be one or 2 octets and contains the V.24 signals
and in the 2 octet case also the break signal.
We were improperly decoding the break signal from the modem in the
2 octet case.
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit b1c43f82c5.
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 a5660b41af: "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 a5660b41af.
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>
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (48 commits)
serial: 8250_pci: add support for Cronyx Omega PCI multiserial board.
tty/serial: Fix break handling for PORT_TEGRA
tty/serial: Add explicit PORT_TEGRA type
n_tracerouter and n_tracesink ldisc additions.
Intel PTI implementaiton of MIPI 1149.7.
Kernel documentation for the PTI feature.
export kernel call get_task_comm().
tty: Remove to support serial for S5P6442
pch_phub: Support new device ML7223
8250_pci: Add support for the Digi/IBM PCIe 2-port Adapter
ASoC: Update cx20442 for TTY API change
pch_uart: Support new device ML7223 IOH
parport: Use request_muxed_region for IT87 probe and lock
tty/serial: add support for Xilinx PS UART
n_gsm: Use print_hex_dump_bytes
drivers/tty/moxa.c: Put correct tty value
TTY: tty_io, annotate locking functions
TTY: serial_core, remove superfluous set_task_state
TTY: serial_core, remove invalid test
Char: moxa, fix locking in moxa_write
...
Fix up trivial conflicts in drivers/bluetooth/hci_ldisc.c and
drivers/tty/serial/Makefile.
I did the hci_ldisc thing as an evil merge, cleaning things up.
Use the standard mechanism to print a hex buffer
to eliminate empty printf warning.
A couple % smaller text and data too.
$ size drivers/tty/n_gsm.o*
text data bss dec hex filename
23543 312 6376 30231 7617 drivers/tty/n_gsm.o.new
24051 408 6496 30955 78eb drivers/tty/n_gsm.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
Problem description:
gsm_queue() calculate a CRC for arrived frames. As a last step of
CRC calculation it call
gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs);
This work perfectly for the case of GSM0 mode as gsm->received_fcs
contain the last piece of data required to generate final CRC.
gsm->received_fcs is not used for GSM1 mode. Thus we put an
additional byte to CRC calculation. As result we get a wrong CRC
and reject incoming frame.
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* the GSM 07.10 specification says in 5.4.3.1 that
'both stations shall set the P bit to 0'
thanks to Alan Cox for finding this explanation in the spec
* without this fix, on Telit & Sim.com modems, opening a new DLC
randomly fails. Not setting PF bit of the control byte gives a
reliable behaviour on these modems.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Doing tiocmget was such fun we should do tiocmset as well for the same
reasons
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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 <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This field is settable but did not get copied.
Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (36 commits)
serial: apbuart: Fixup apbuart_console_init()
TTY: Add tty ioctl to figure device node of the system console.
tty: add 'active' sysfs attribute to tty0 and console device
drivers: serial: apbuart: Handle OF failures gracefully
Serial: Avoid unbalanced IRQ wake disable during resume
tty: fix typos/errors in tty_driver.h comments
pch_uart : fix warnings for 64bit compile
8250: fix uninitialized FIFOs
ip2: fix compiler warning on ip2main_pci_tbl
specialix: fix compiler warning on specialix_pci_tbl
rocket: fix compiler warning on rocket_pci_ids
8250: add a UPIO_DWAPB32 for 32 bit accesses
8250: use container_of() instead of casting
serial: omap-serial: Add support for kernel debugger
serial: fix pch_uart kconfig & build
drivers: char: hvc: add arm JTAG DCC console support
RS485 documentation: add 16C950 UART description
serial: ifx6x60: fix memory leak
serial: ifx6x60: free IRQ on error
Serial: EG20T: add PCH_UART driver
...
Fixed up conflicts in drivers/serial/apbuart.c with evil merge that
makes the code look fairly sane (unlike either side).
gsm_data_alloc buffer allocation could fail and it is not being checked.
Add check for allocated buffer and return if the buffer allocation
fails.
Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix message length handling when building header
When the message length is greater than 127, the length field in the header
is built incorrectly. According to the spec, when the length is less than 128
the length field is a single byte formatted as: bbbbbbb1. When it is greater
than 127 then the field is two bytes of the format: bbbbbbb0 bbbbbbbb.
Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[Original From Ken Mills but I redid it using pr_ helpers instead]
Also fix up coding style, there are two warnings left but that is where
the CodingStyle tools blow up because they cannot handle
if (blah) {
foo
} else switch (x) {
case 1:
}
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The mux supports several encoding schemes. Encoding 0 is a "not
recommended" mode still sometimes used. This has now been tested with
hardware that supports this mode, and found wanting.
Fix the FCS handling in this mode and correct the state machine.
Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
If the mux is configured with a large mru/mtu the existing code gets the
byte ordering wrong for the header.
Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The n2 field is settable but didn't get propogated
Signed-off-by: Ken Mills <ken.k.mills@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
