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path: root/drivers/tty/ipwireless/tty.c
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2014-02-28tty: Fix low_latency BUGPeter Hurley
The user-settable knob, low_latency, has been the source of several BUG reports which stem from flush_to_ldisc() running in interrupt context. Since 3.12, which added several sleeping locks (termios_rwsem and buf->lock) to the input processing path, the frequency of these BUG reports has increased. Note that changes in 3.12 did not introduce this regression; sleeping locks were first added to the input processing path with the removal of the BKL from N_TTY in commit a88a69c91256418c5907c2f1f8a0ec0a36f9e6cc, 'n_tty: Fix loss of echoed characters and remove bkl from n_tty' and later in commit 38db89799bdf11625a831c5af33938dcb11908b6, 'tty: throttling race fix'. Since those changes, executing flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe. However, since most devices do not validate if the low_latency setting is appropriate for the context (process or interrupt) in which they receive data, some reports are due to misconfiguration. Further, serial dma devices for which dma fails, resort to interrupt receiving as a backup without resetting low_latency. Historically, low_latency was used to force wake-up the reading process rather than wait for the next scheduler tick. The effect was to trim multiple milliseconds of latency from when the process would receive new data. Recent tests [1] have shown that the reading process now receives data with only 10's of microseconds latency without low_latency set. Remove the low_latency rx steering from tty_flip_buffer_push(); however, leave the knob as an optional hint to drivers that can tune their rx fifos and such like. Cleanup stale code comments regarding low_latency. [1] https://lkml.org/lkml/2014/2/20/434 "Yay.. thats an annoying historical pain in the butt gone." -- Alan Cox Reported-by: Beat Bolli <bbolli@ewanet.ch> Reported-by: Pavel Roskin <proski@gnu.org> Acked-by: David Sterba <dsterba@suse.cz> Cc: Grant Edwards <grant.b.edwards@gmail.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Hal Murray <murray+fedora@ip-64-139-1-69.sjc.megapath.net> Cc: <stable@vger.kernel.org> # 3.12.x+ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-07tty: delete non-required instances of include <linux/init.h>Paul Gortmaker
None of these files are actually using any __init type directives and hence don't need to include <linux/init.h>. Most are just a left over from __devinit and __cpuinit removal, or simply due to code getting copied from one driver to the next. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.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: move low_latency to tty_portJiri Slaby
One point is to have less places where we actually need tty pointer. The other is that low_latency is bound to buffer processing and buffers are now in tty_port. So it makes sense to move low_latency to tty_port too. 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>
2012-11-15TTY: call tty_port_destroy in the rest of driversJiri 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. To be sure, the TTY buffers (and later some stuff) are gone along with the tty_port, we have to call tty_port_destroy at tear-down places. This is mostly where the structure containing a tty_port is freed. This patch does exactly that -- put tty_port_destroy at those places. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-13TTY: use tty_port_register_deviceJiri Slaby
Currently we have no way to assign tty->port while performing tty installation. There are two ways to provide the link tty_struct => tty_port. Either by calling tty_port_install from tty->ops->install or tty_port_register_device called instead of tty_register_device when the device is being set up after connected. In this patch we modify most of the drivers to do the latter. When the drivers use tty_register_device and we have tty_port already, we switch to tty_port_register_device. So we have the tty_struct => tty_port link for free for those. 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>
2012-04-09TTY: ipwireless, use tty from tty_portJiri Slaby
It does not make the driver less racy though. Close and hangup should be rewritten and tty refcounting used properly. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Jiri Kosina <jkosina@suse.cz> Acked-by: David Sterba <dsterba@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09TTY: ipwireless, add tty_portJiri Slaby
And use count from that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Jiri Kosina <jkosina@suse.cz> Acked-by: David Sterba <dsterba@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09TTY: ipwireless, move prints to appropriate placesJiri Slaby
There are two functions which only print a status. Let us do that directly at places where they are called. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Jiri Kosina <jkosina@suse.cz> Acked-by: David Sterba <dsterba@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09TTY: ipwireless, use synchronous hangupJiri Slaby
Do not touch internal workqueue. Call tty_vhangup instead. Note that finished hangup does not necessarily mean that all processes are dead. Especially when the tty is a console. The code assumes that right now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Jiri Kosina <jkosina@suse.cz> Acked-by: David Sterba <dsterba@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking merge from David Miller: "1) Move ixgbe driver over to purely page based buffering on receive. From Alexander Duyck. 2) Add receive packet steering support to e1000e, from Bruce Allan. 3) Convert TCP MD5 support over to RCU, from Eric Dumazet. 4) Reduce cpu usage in handling out-of-order TCP packets on modern systems, also from Eric Dumazet. 5) Support the IP{,V6}_UNICAST_IF socket options, making the wine folks happy, from Erich Hoover. 6) Support VLAN trunking from guests in hyperv driver, from Haiyang Zhang. 7) Support byte-queue-limtis in r8169, from Igor Maravic. 8) Outline code intended for IP_RECVTOS in IP_PKTOPTIONS existed but was never properly implemented, Jiri Benc fixed that. 9) 64-bit statistics support in r8169 and 8139too, from Junchang Wang. 10) Support kernel side dump filtering by ctmark in netfilter ctnetlink, from Pablo Neira Ayuso. 11) Support byte-queue-limits in gianfar driver, from Paul Gortmaker. 12) Add new peek socket options to assist with socket migration, from Pavel Emelyanov. 13) Add sch_plug packet scheduler whose queue is controlled by userland daemons using explicit freeze and release commands. From Shriram Rajagopalan. 14) Fix FCOE checksum offload handling on transmit, from Yi Zou." * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1846 commits) Fix pppol2tp getsockname() Remove printk from rds_sendmsg ipv6: fix incorrent ipv6 ipsec packet fragment cpsw: Hook up default ndo_change_mtu. net: qmi_wwan: fix build error due to cdc-wdm dependecy netdev: driver: ethernet: Add TI CPSW driver netdev: driver: ethernet: add cpsw address lookup engine support phy: add am79c874 PHY support mlx4_core: fix race on comm channel bonding: send igmp report for its master fs_enet: Add MPC5125 FEC support and PHY interface selection net: bpf_jit: fix BPF_S_LDX_B_MSH compilation net: update the usage of CHECKSUM_UNNECESSARY fcoe: use CHECKSUM_UNNECESSARY instead of CHECKSUM_PARTIAL on tx net: do not do gso for CHECKSUM_UNNECESSARY in netif_needs_gso ixgbe: Fix issues with SR-IOV loopback when flow control is disabled net/hyperv: Fix the code handling tx busy ixgbe: fix namespace issues when FCoE/DCB is not enabled rtlwifi: Remove unused ETH_ADDR_LEN defines igbvf: Use ETH_ALEN ... Fix up fairly trivial conflicts in drivers/isdn/gigaset/interface.c and drivers/net/usb/{Kconfig,qmi_wwan.c} as per David.
2012-03-08TTY: ipwireless, fix tty->index handlingJiri Slaby
* do not test if tty->index is in bounds. It is always. * tty->index is not a minor! Fix that. >From now on, let's assume that the parameter of the function is tty index with base being zero. This makes also the code more readable. Factually, there is no real change as tty_driver->minor_start is zero, so the tests are equivalent. But it did not make sense. And if this had changed eventually, it would have caused troubles. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Cc: David Sterba <dsterba@suse.cz> 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>
2012-03-04ppp: Replace uses of <linux/if_ppp.h> with <linux/ppp-ioctl.h>Paul Mackerras
Since all that include/linux/if_ppp.h does is #include <linux/ppp-ioctl.h>, this replaces the occurrences of #include <linux/if_ppp.h> with #include <linux/ppp-ioctl.h>. It also corrects an error in Documentation/networking/l2tp.txt, where it referenced include/linux/if_ppp.h as the source of some definitions that are actually now defined in include/linux/if_pppol2tp.h. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-22tty: move ipwireless driver from drivers/char/pcmcia/ to drivers/tty/Greg Kroah-Hartman
As planned by Arnd Bergmann, this moves the ipwireless driver to the drivers/tty/ directory as that's where it really belongs. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Jiri Slaby <jslaby@suse.cz> Cc: David Sterba <dsterba@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>