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path: root/drivers/tty/n_gsm.c
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2014-02-07tty: n_gsm: Fix for modems with brk in modem status controlLars Poeschel
3GPP TS 07.10 states in section 5.4.6.3.7: "The length byte contains the value 2 or 3 ... depending on the break signal." The break byte is optional and if it is sent, the length is 3. In fact the driver was not able to work with modems that send this break byte in their modem status control message. If the modem just sends the break byte if it is really set, then weird things might happen. The code for deconding the modem status to the internal linux presentation in gsm_process_modem has already a big comment about this 2 or 3 byte length thing and it is already able to decode the brk, but the code calling the gsm_process_modem function in gsm_control_modem does not encode it and hand it over the right way. This patch fixes this. Without this fix if the modem sends the brk byte in it's modem status control message the driver will hang when opening a muxed channel. Signed-off-by: Lars Poeschel <poeschel@lemonage.de> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-18TTY/n_gsm: Removing the wrong tty_unlock/lock() in gsm_dlci_release()Chuansheng Liu
Commit 4d9b109060f690f5c835(tty: Prevent deadlock in n_gsm driver) tried to close all the virtual ports synchronously before closing the phycial ports, so the tty_vhangup() is used. But the tty_unlock/lock() is wrong: tty_release tty_ldisc_release tty_lock_pair(tty, o_tty) < == Here the tty is for physical port tty_ldisc_kill gsmld_close gsm_cleanup_mux gsm_dlci_release tty = tty_port_tty_get(&dlci->port) < == Here the tty(s) are for virtual port They are different ttys, so before tty_vhangup(virtual tty), do not need to call the tty_unlock(virtual tty) at all which causes unbalanced unlock warning. When enabling mutex debugging option, we will hit the below warning also: [ 99.276903] ===================================== [ 99.282172] [ BUG: bad unlock balance detected! ] [ 99.287442] 3.10.20-261976-gaec5ba0 #44 Tainted: G O [ 99.293972] ------------------------------------- [ 99.299240] mmgr/152 is trying to release lock (&tty->legacy_mutex) at: [ 99.306693] [<c1b2dcad>] mutex_unlock+0xd/0x10 [ 99.311669] but there are no more locks to release! [ 99.317131] [ 99.317131] other info that might help us debug this: [ 99.324440] 3 locks held by mmgr/152: [ 99.328542] #0: (&tty->legacy_mutex/1){......}, at: [<c1b30ab0>] tty_lock_nested+0x40/0x90 [ 99.338116] #1: (&tty->ldisc_mutex){......}, at: [<c15dbd02>] tty_ldisc_kill+0x22/0xd0 [ 99.347284] #2: (&gsm->mutex){......}, at: [<c15e3d83>] gsm_cleanup_mux+0x73/0x170 [ 99.356060] [ 99.356060] stack backtrace: [ 99.360932] CPU: 0 PID: 152 Comm: mmgr Tainted: G O 3.10.20-261976-gaec5ba0 #44 [ 99.370086] ef4a4de0 ef4a4de0 ef4c1d98 c1b27b91 ef4c1db8 c1292655 c1dd10f5 c1b2dcad [ 99.378921] c1b2dcad ef4a4de0 ef4a528c ffffffff ef4c1dfc c12930dd 00000246 00000000 [ 99.387754] 00000000 00000000 c15e1926 00000000 00000001 ddfa7530 00000003 c1b2dcad [ 99.396588] Call Trace: [ 99.399326] [<c1b27b91>] dump_stack+0x16/0x18 [ 99.404307] [<c1292655>] print_unlock_imbalance_bug+0xe5/0xf0 [ 99.410840] [<c1b2dcad>] ? mutex_unlock+0xd/0x10 [ 99.416110] [<c1b2dcad>] ? mutex_unlock+0xd/0x10 [ 99.421382] [<c12930dd>] lock_release_non_nested+0x1cd/0x210 [ 99.427818] [<c15e1926>] ? gsm_destroy_network+0x36/0x130 [ 99.433964] [<c1b2dcad>] ? mutex_unlock+0xd/0x10 [ 99.439235] [<c12931a2>] lock_release+0x82/0x1c0 [ 99.444505] [<c1b2dcad>] ? mutex_unlock+0xd/0x10 [ 99.449776] [<c1b2dcad>] ? mutex_unlock+0xd/0x10 [ 99.455047] [<c1b2dc2f>] __mutex_unlock_slowpath+0x5f/0xd0 [ 99.461288] [<c1b2dcad>] mutex_unlock+0xd/0x10 [ 99.466365] [<c1b30bb1>] tty_unlock+0x21/0x50 [ 99.471345] [<c15e3dd1>] gsm_cleanup_mux+0xc1/0x170 [ 99.476906] [<c15e44d2>] gsmld_close+0x52/0x90 [ 99.481983] [<c15db905>] tty_ldisc_close.isra.1+0x35/0x50 [ 99.488127] [<c15dbd0c>] tty_ldisc_kill+0x2c/0xd0 [ 99.493494] [<c15dc7af>] tty_ldisc_release+0x2f/0x50 [ 99.499152] [<c15d572c>] tty_release+0x37c/0x4b0 [ 99.504424] [<c1b2dcad>] ? mutex_unlock+0xd/0x10 [ 99.509695] [<c1b2dcad>] ? mutex_unlock+0xd/0x10 [ 99.514967] [<c1372f6e>] ? eventpoll_release_file+0x7e/0x90 [ 99.521307] [<c1335849>] __fput+0xd9/0x200 [ 99.525996] [<c133597d>] ____fput+0xd/0x10 [ 99.530685] [<c125c731>] task_work_run+0x81/0xb0 [ 99.535957] [<c12019e9>] do_notify_resume+0x49/0x70 [ 99.541520] [<c1b30dc4>] work_notifysig+0x29/0x31 [ 99.546897] ------------[ cut here ]------------ So here we can call tty_vhangup() directly which is for virtual port. Reviewed-by: Chao Bi <chao.bi@intel.com> Signed-off-by: Liu, Chuansheng <chuansheng.liu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-17drivers: tty: Mark the functions as static in n_gsm.cRashika Kheria
Marks the functions gsm_cleanup_mux(), gsm_activate_mux(), gsm_free_mux(), gsm_alloc_mux() and gsm_change_mtu() as static in n_gsm.c because they are not used outside this file. Also, drop the EXPORT_SYMBOL_GPL for the above mentioned functions because nothing else in the kernel calls them. This eliminates the following warnings in n_gsm.c: drivers/tty/n_gsm.c:2022:6: warning: no previous prototype for ‘gsm_cleanup_mux’ [-Wmissing-prototypes] drivers/tty/n_gsm.c:2076:5: warning: no previous prototype for ‘gsm_activate_mux’ [-Wmissing-prototypes] drivers/tty/n_gsm.c:2120:6: warning: no previous prototype for ‘gsm_free_mux’ [-Wmissing-prototypes] drivers/tty/n_gsm.c:2156:17: warning: no previous prototype for ‘gsm_alloc_mux’ [-Wmissing-prototypes] drivers/tty/n_gsm.c:2714:5: warning: no previous prototype for ‘gsm_change_mtu’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08n_gsm: race between ld close and gsmtty openChao Bi
ttyA has ld associated to n_gsm, when ttyA is closing, it triggers to release gsmttyB's ld data dlci[B], then race would happen if gsmttyB is opening in parallel. (Note: This patch set differs from previous set in that it uses mutex instead of spin lock to avoid race, so that it avoids sleeping in automic context) Here are race cases we found recently in test: CASE #1 ==================================================================== releasing dlci[B] race with gsmtty_install(gsmttyB), then panic in gsmtty_open(gsmttyB), as below: tty_release(ttyA) tty_open(gsmttyB) | | ----- gsmtty_install(gsmttyB) | | ----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B] tty_ldisc_release(ttyA) ----- | | gsm_dlci_release(dlci[B]) ----- | | gsm_dlci_free(dlci[B]) ----- | | ----- gsmtty_open(gsmttyB) gsmtty_open() { struct gsm_dlci *dlci = tty->driver_data; => here it uses dlci[B] ... } In gsmtty_open(gsmttyA), it uses dlci[B] which was release, so hit a panic. ===================================================================== CASE #2 ===================================================================== releasing dlci[0] race with gsmtty_install(gsmttyB), then panic in gsmtty_open(), as below: tty_release(ttyA) tty_open(gsmttyB) | | ----- gsmtty_install(gsmttyB) | | ----- gsm_dlci_alloc(gsmttyB) => alloc dlci[B] | | ----- gsmtty_open(gsmttyB) fail | | ----- tty_release(gsmttyB) | | ----- gsmtty_close(gsmttyB) | | ----- gsmtty_detach_dlci(dlci[B]) | | ----- dlci_put(dlci[B]) | | tty_ldisc_release(ttyA) ----- | | gsm_dlci_release(dlci[0]) ----- | | gsm_dlci_free(dlci[0]) ----- | | ----- dlci_put(dlci[0]) In gsmtty_detach_dlci(dlci[B]), it tries to use dlci[0] which was released, then hit panic. ===================================================================== IMHO, n_gsm tty operations would refer released ldisc, as long as gsm_dlci_release() has chance to release ldisc data when some gsmtty operations are ongoing.. This patch is try to avoid it by: 1) in n_gsm driver, use a global gsm mutex lock to avoid gsm_dlci_release() run in parallel with gsmtty_install(); 2) Increase dlci's ref count in gsmtty_install() instead of in gsmtty_open(), the purpose is to prevent gsm_dlci_release() releasing dlci after gsmtty_install() allocats dlci but before gsmtty_open increases dlci's ref count; 3) Decrease dlci's ref count in gsmtty_remove(), a tty framework API, this is the opposite process of step 2). Signed-off-by: Chao Bi <chao.bi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08tty: Always handle NULL flag ptrPeter Hurley
Most line disciplines already handle the undocumented NULL flag ptr in their .receive_buf method; however, several don't. Document the NULL flag ptr, and correct handling in the N_MOUSE, N_GSM0710 and N_R394 line disciplines. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-24Drivers: tty: n_gsm.c: fixed 7 errors & 6 warnings that checkpatch complainedAldo Iljazi
Specifically: n_gsm.c:810: ERROR: space required before the open parenthesis '(' n_gsm.c:830: WARNING: line over 80 characters n_gsm.c:971: ERROR: trailing whitespace n_gsm.c:984: ERROR: code indent should use tabs where possible n_gsm.c:984: WARNING: please, no space before tabs n_gsm.c:984: WARNING: please, no spaces at the start of a line n_gsm.c:1141: WARNING: space prohibited before semicolon n_gsm.c:1743: ERROR: space required before the open brace '{' n_gsm.c:1744: WARNING: line over 80 characters n_gsm.c:1745: ERROR: code indent should use tabs where possible n_gsm.c:1746: ERROR: code indent should use tabs where possible n_gsm.c:2908: WARNING: line over 80 characters n_gsm.c:2912: ERROR: trailing whitespace Signed-off-by: Aldo Iljazi <neonsync1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: fix DTR not being dropped on hang upJohan Hovold
Move HUPCL handling to port shutdown so that DTR is dropped also on hang up (tty_port_close is a noop for hung-up ports). Also do not try to drop DTR for uninitialised ports where it has never been raised (e.g. after a failed open). Note that this is also the current behaviour of serial-core. Nine drivers currently call tty_port_close_start directly (rather than through tty_port_close) and seven of them lower DTR as part of their close (if the port has been initialised). Fixup the remaining two drivers so that it continues to be lowered also on normal (non-HUP) close. [ Note that most of those other seven drivers did not expect DTR to have been dropped by tty_port_close_start in the first place. ] Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-18TTY: add tty_port_tty_hangup helperJiri Slaby
It allows for cleaning up on a considerable amount of places. They did port_get, hangup, kref_put. Now the only thing needed is to call tty_port_tty_hangup which does exactly that. And they can also decide whether to consider CLOCAL or completely ignore that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-30tty: Prevent deadlock in n_gsm driverDirkjan Bussink
This change fixes a deadlock when the multiplexer is closed while there are still client side ports open. When the multiplexer is closed and there are active tty's it tries to close them with tty_vhangup. This has a problem though, because tty_vhangup needs the tty_lock. This patch changes it to unlock the tty_lock before attempting the hangup and relocks afterwards. The additional call to tty_port_tty_set is needed because otherwise the port stays active because of the reference counter. This change also exposed another problem that other code paths don't expect that the multiplexer could have been closed. This patch also adds checks for these cases in the gsmtty_ class of function that could be called. The documentation explicitly states that "first close all virtual ports before closing the physical port" but we've found this to not always reality in our field situations. The GPRS / UTMS modem sometimes crashes and needs a power cycle in that case which means cleanly shutting down everything is not always possible. This change makes it much more robust for our situation where at least the system is recoverable with this patch and doesn't hang in a deadlock situation inside the kernel. The patch is against the long term support kernel (3.4.27) and should apply cleanly to more recent branches. Tested with a Telit GE864-QUADV2 and Telit HE910 modem. Signed-off-by: Dirkjan Bussink <dirkjan.bussink@nedap.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15Revert "n_gsm.c: add tx_lock in gsm_send"Greg Kroah-Hartman
This reverts commit f96f7f7f39af53274d98aa9c29d6fa4d122218a4, at the request of Jin. Cc: xiaojin <jin.xiao@intel.com> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_flip_buffer_pushJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. Now, the one where most of tty_port_tty_get gets removed: tty_flip_buffer_push. IOW we also closed all the races in drivers not using tty_port_tty_get at all yet. Also we move tty_flip_buffer_push declaration from include/linux/tty.h to include/linux/tty_flip.h to all others while we are changing it anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_insert_flip_stringJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_string this time. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15TTY: switch tty_insert_flip_charJiri Slaby
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_char is the next one to proceed. This one is used all over the code, so the patch is huge. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-15n_gsm.c: add tx_lock in gsm_sendxiaojin
All the call to gsm->output should be in the tx_lock, that could avoid potential race from MUX level. But we have no tx_lock in gsm_send. This patch is to add tx_lock in gsm_send. Signed-off-by: xiaojin <jin.xiao@intel.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-15TTY: n_gsm, use kref from tty_portJiri Slaby
After commit "TTY: move tty buffers to tty_port", the tty buffers are not freed in some drivers. This is because tty_port_destructor is not called whenever a tty_port is freed. This was an assumption I counted with but was unfortunately untrue. So fix the drivers to fulfil this assumption. Here it is enough to switch to refcounting in tty_port. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-17tty: n_gsm: Fix incorrect debug displayAlan Cox
In the trace we print the wrong values for N(R) on an I frame. Correct the mask. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16n_gsm: memory leak in uplink error pathRuss Gorby
Uplink (TX) network data will go through gsm_dlci_data_output_framed there is a bug where if memory allocation fails, the skb which has already been pulled off the list will be lost. In addition TX skbs were being processed in LIFO order Fixed the memory leak, and changed to FIFO order processing Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Kappel, LaurentX <laurentx.kappel@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Showjumping <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16n_gsm: replace kfree_skb w/ appropriate dev_* versionsRuss Gorby
Drivers are supposed to use the dev_* versions of the kfree_skb interfaces. In a couple of cases we were called with IRQs disabled as well which kfree_skb() does not expect. Replaced kfree_skb calls w/ dev_kfree_skb and dev_kfree_skb_any Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Grooming <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16n_gsm: avoid accessing freed memory during CMD_FCOFF conditionRuss Gorby
gsm_data_kick was recently modified to allow messages on the tx queue bound for DLCI0 to flow even during FCOFF conditions. Unfortunately we introduced a bug discovered by code inspection where subsequent list traversers can access freed memory if the DLCI0 messages were not all at the head of the list. Replaced singly linked tx list w/ a list_head and used provided interfaces for traversing and deleting members. Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Riding School <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16n_gsm: added interlocking for gsm_data_lock for certain code pathsRuss Gorby
There were some locking holes in the management of the MUX's message queue for 2 code paths: 1) gsmld_write_wakeup 2) receipt of CMD_FCON flow-control message In both cases gsm_data_kick is called w/o locking so it can collide with other other instances of gsm_data_kick (pulling messages tx_tail) or potentially other instances of __gsm_data_queu (adding messages to tx_head) Changed to take the tx_lock in these 2 cases Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Riding School <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16char: n_gsm: remove message filtering for contipated DLCIsamix.lebsir
The design of uplink flow control in the mux driver is that for constipated channels data will backup into the per-channel fifos, and any messages that make it to the outbound message queue will still go out. Code was added to also stop messages that were in the outbound queue but this requires filtering through all the messages on the queue for stopped dlcis and changes some of the mux logic unneccessarily. The message fiiltering was removed to be in line w/ the original design as the message filtering does not provide any solution. Extra debug messages used during investigation were also removed. Signed-off-by: samix.lebsir <samix.lebsir@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Dressage <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16n_gsm : Flow control handling in Mux driverFrederic Berat
- Correcting handling of FCon/FCoff in order to respect 27.010 spec - Consider FCon/off will overide all dlci flow control except for dlci0 as we must be able to send control frames. - Dlci constipated handling according to FC, RTC and RTR values. - Modifying gsm_dlci_data_kick and gsm_dlci_data_sweep according to dlci constipated value Signed-off-by: Frederic Berat <fredericx.berat@intel.com> Signed-off-by: Russ Gorby <russ.gorby@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16n_gsm: uplink SKBs accumulate on listRuss Gorby
gsm_dlci_data_kick will not call any output function if tx_bytes > THRESH_LO furthermore it will call the output function only once if tx_bytes == 0 If the size of the IP writes are on the order of THRESH_LO we can get into a situation where skbs accumulate on the outbound list being starved for events to call the output function. gsm_dlci_data_kick now calls the sweep function when tx_bytes==0 Signed-off-by: Russ Gorby <russ.gorby@intel.com> Tested-by: Kappel, LaurentX <laurentx.kappel@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Hay and Water <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-16n_gsm.c: Implement 3GPP27.010 DLC start-up procedure in MUXxiaojin
In 3GPP27.010 5.8.1, it defined: The TE multiplexer initiates the establishment of the multiplexer control channel by sending a SABM frame on DLCI 0 using the procedures of clause 5.4.1. Once the multiplexer channel is established other DLCs may be established using the procedures of clause 5.4.1. This patch implement 5.8.1 in MUX level, it make sure DLC0 is the first channel to be setup. [or for those not familiar with the specification: it was possible to try and open a data connection while the control channel was not yet fully open, which is a spec violation and confuses some modems] Signed-off-by: xiaojin <jin.xiao@intel.com> Tested-by: Yin, Fengwei <fengwei.yin@intel.com> [tweaked the order we check things and error code] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: The Horsebox <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-10TTY: n_gsm, use tty_port_installJiri Slaby
We need to link a port to a tty in install. And since dlci is allocated even in open, we need to create gsmtty_install, allocate dlci there and create also the link. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16tty: move the termios object into the ttyAlan Cox
This will let us sort out a whole pile of tty related races. The alternative would be to keep points and refcount the termios objects. However 1. They are tiny anyway 2. Many devices don't use the stored copies 3. We can remove a pty special case Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08TTY: remove re-assignments to tty_driver membersJiri Slaby
All num, magic and owner are set by alloc_tty_driver. No need to re-set them on each allocation site. pti driver sets something different to what it passes to alloc_tty_driver. It is not a bug, since we don't use the lines parameter in any way. Anyway this is fixed, and now we do the right thing. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Tilman Schmidt <tilman@imap.cc> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-11-08n_gsm: Fix timingsAlan Cox
Alek Du reported that the code erroneously applies time to jiffies conversions twice to the t1 and t2 values. In normal use on a modem link this cases no visible problem but on a slower link it will break as with HZ=1000 as is typical we are running t1/t2 ten times too fast. Alek's original patch removed the conversion from the timer setting but we in fact have to be more careful as the contents of t1/t2 are visible via the device API and we thus need to correct the constants. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-26tty/n_gsm: avoid fifo overflow in gsm_dlci_data_outputMikhail Kshevetskiy
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>
2011-09-26tty/n_gsm: fix a bug in gsm_dlci_data_output (adaption = 2 case)Mikhail Kshevetskiy
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>
2011-09-26tty/n_gsm: fix bug in tiocmsetNikola Diklic-Perin
Clear bitmask was not inverted before masking modem_tx. Calling ioctl(fd, TIOCMBIC, TIOCM_RTS) results in: [ 197.430000] pre_modem_tx: 0x00000006 [ 197.430000] clear: 0x00000004 [ 197.430000] set: 0x00000000 [ 197.440000] post_modem_tx: 0x00000004 which is wrong. Signed-off-by: Nikola Diklic-Perin <diklic.perin.nikola@gmail.com> Acked-by: Alan Cox <alan@linx.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-26n_gsm: Send CLD command on exitAlan Cox
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>
2011-08-26n_gsm: update TODO listAlan Cox
This is now out of date so fix it Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-07-25Merge branch 'tty-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 * '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 ...
2011-07-08n_gsm: fix the wrong FCS handlingDu, Alek
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>
2011-07-01tty: n_gsm: Added refcount usage to gsm_mux and gsm_dlci structsRuss Gorby
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>
2011-07-01tty: n_gsm: Add raw-ip supportRuss Gorby
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>
2011-07-01tty: n_gsm: expose gsmtty device nodes at ldisc open timeRuss Gorby
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>
2011-06-16tty: n_gsm: improper skb_pull() use was leaking framed dataRuss Gorby
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>
2011-06-16tty: n_gsm: Fixed logic to decode break signal from modem statusRuss Gorby
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>
2011-06-04Revert "tty: make receive_buf() return the amout of bytes received"Linus Torvalds
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>
2011-05-23Merge branch 'tty-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6 * '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.
2011-05-10treewide: fix a few typos in commentsJustin P. Mattock
- kenrel -> kernel - whetehr -> whether - ttt -> tt - sss -> ss Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-29n_gsm: Use print_hex_dump_bytesJoe Perches
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>
2011-04-22tty: make receive_buf() return the amout of bytes receivedFelipe Balbi
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>
2011-04-19tty/n_gsm: fix bug in CRC calculation for gsm1 modeMikhail Kshevetskiy
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>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-09n_gsm: fix UIH control byte : P bit should be 0Eric Bénard
* 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>
2011-02-24Merge 2.6.38-rc6 into tty-nextGreg Kroah-Hartman
This was to resolve a merge issue with drivers/char/Makefile and drivers/tty/serial/68328serial.c Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17tty: now phase out the ioctl file pointer for goodAlan Cox
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>