The modem ioctls are not routed via the ioctl method so kill the old dead
code. The correct code is also already present and hooked in.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I made a correction for get_lsr_info, now it returns some meaningful
information. I tested it with two simultaneous simplex modem channels.
it is attached
Signed-off-by: Kees Schoenmakers <k.schoenmakers@sigmae.nl>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix the tiocmget/mset handling on the mos7720 USB serial port.
[Minor space reformatting for coding style - Alan]
Signed-off-by: Kees Schoenmakers <k.schoenmakers@sigmae.nl>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Currently kfifo cannot be used by parts of the kernel that use "const"
properly as kfifo itself does not use const for passed data blocks which
are indeed const.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The network layer now has a destructor we can hook to clean up the slip
devices array. That needs us to initiate unregister events in the right
places which with the current tty layer we can do, and with network
refcounting is safe to do.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove duplicated code from cy_set_line_char. There were 2 if
branches with same contents except flags.
Branch only for the flags computation and use them in the only copy
of the code.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add helpers for io operations, so that we can eliminate huge
amount of supporting code. It is now centralized in those
helpers and used values are precomputed in the init phase.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- save one indent level by inverting !fw_loaded condition
- read rs_status on Z and write it after we change all the flags,
don't do that separately
- remove Y inverted rts/dtr branching, precompute registers and use
them
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- add a cy_ prefix to functions with changed prototypes
- cy_get_serial_info: initialize serial_struct by initializer,
save a memset
- inline simple functions (get_mon_info, {s,g}et_default_threshold,
{s,g}et_default_timeout) directly in the ioctl handler
- add a cy_cflags_changed helper to not copy its code by
wait_event_interruptible
- remove some ret_val = 0 assignments, it's preset to 0
- TIOCGICOUNT: don't do many put_user's, do one copy_to_user
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is a duplicated code for Y and Z in cy_startup, merge the paths.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For Z cards, use tty helpers for dtr_rts.
If we did the same for Y cards, it will cause a deadlock, because
cyy_dtr_rts takes a lock which we already hold.
Instead, we introduce a Y helper expecting card lock to be held.
It may then be called with set/clear masks from other places.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Avoid long busy loops (5 ms) which may be replaced by sleeps.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- remove changelog from the file. we don't care about ancient
history
- update copyright year
- update version
- constify some stuff
- empty lines removal
- unused variables and macros removal
- remove some asm/ includes, they are sucked by linux/ variants
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use new tty helpers for close, which allows much code removal.
The only real change is locking. card_lock for protecting was
used inappropriately (just to have a critical section, no matter
which lock is used), so the change to port->lock is fine.
Remove also useless debug printks while being there.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Do not duplicate common tty_port_hangup code. Use it instead.
Also do not unset ASYNC_NORMAL_ACTIVE and wake up from the
tty_hangup() caller. It makes no sense since we don't check that
flag in sleepers. tty_port_hangup() performed later will do the
right job.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Don't fetch firmware address and recompute channel control on each
port access. Precompute the values on init and use them later all
the time.
The same for board control.
This simplify code and improves readability.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use a tty_port common instead. This saves lots of .text and makes the
code a lot more readable.
This involves separation of a dtr_rts handling, next patches will use
that to not duplicate the code all over the place.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
While this is not problem for Y card handlers (they are protected
by card_lock), Z handlers and other functions may dereference NULL
at any point after hangup/close. Even if (tty == NULL) was already
performed in the handler.
Note that it's not an issue for Y cards just for now. After
switching to tty_port_close_* et al. this will be a problem. So
add refcounting to them all.
Also proc .show doesn't take a tty reference and it should (along
with a ldisc one).
While at it and changing prototypes (adding tty param), prepend
cy_ to functions which don't have it yet.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Previously, if any bit other than CMD_SND_BREAK was set, CMD_SND_BREAK
was not unset.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fix the following 'make includecheck' warning:
drivers/char/vt.c: linux/device.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the /proc/tty/ldiscs handling doesn't play games with 'struct
ldisc' any more, the only remaining user of 'tty_ldisc_try_get()' is
'tty_ldisc_get()' (note the lack of 'try').
And we're actually much better off folding the logic directly into that
file, since the 'try' part was always about trying to get the ldisc
operations, not the ldisc itself: and making that explicit inside of
'tty_ldisc_get()' clarifies the whole semantics.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The /proc/tty/ldiscs file is totally and utterly un-interested in the
"struct tty_ldisc" structures, and only cares about the underlying ldisc
operations.
So don't make it create a dummy 'struct ldisc' only to get a pointer to
the operations, and then destroy it. Instead, we split up the function
'tty_ldisc_try_get()', and create a 'get_ldops()' helper that just looks
up the ldisc operations based on the ldisc number.
That makes the code simpler to read (smaller and more well-defined
helper functions), and allows the /proc functions to avoid creating that
useless dummy only to immediately free it again.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since early printk only makes sense/works when the serial driver is built
into the kernel, disable the option for this driver when it is going to be
built as a module. Otherwise we get build failures due to the ifdef
handling.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: stable <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The tty_operation chars_in_buffer() is not allowed to return a negative
value to signal an error. Corrects the problem flagged by commit
23198fda71, "tty: fix chars_in_buffers".
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits)
x86: Move get/set_wallclock to x86_platform_ops
x86: platform: Fix section annotations
x86: apic namespace cleanup
x86: Distangle ioapic and i8259
x86: Add Moorestown early detection
x86: Add hardware_subarch ID for Moorestown
x86: Add early platform detection
x86: Move tsc_init to late_time_init
x86: Move tsc_calibration to x86_init_ops
x86: Replace the now identical time_32/64.c by time.c
x86: time_32/64.c unify profile_pc
x86: Move calibrate_cpu to tsc.c
x86: Make timer setup and global variables the same in time_32/64.c
x86: Remove mca bus ifdef from timer interrupt
x86: Simplify timer_ack magic in time_32.c
x86: Prepare unification of time_32/64.c
x86: Remove do_timer hook
x86: Add timer_init to x86_init_ops
x86: Move percpu clockevents setup to x86_init_ops
x86: Move xen_post_allocator_init into xen_pagetable_setup_done
...
Fix up conflicts in arch/x86/include/asm/io_apic.h
Signed-off-by: Geoffrey Thomas <geofft@ksplice.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is largely a straightforward conversion. The patch results in
fewer output sections, and some data being reordered, but should have
no functional impact.
Also, note that this patch moves some data (namely, init_task and
cacheline-aligned) inside [_sdata,_edata].
Because frv already builds using -ffunction-sections -fdata-sections,
we can't use BSS_SECTION or RW_DATA_SECTION yet, since they do not
currently include the required .bss.* and .data.* sections.
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It appears that frv copied the .altinstructions definitions in its linker
script from x86. Since frv doesn't put anything in those sections, this
is just dead code.
Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (64 commits)
ext4: Update documentation about quota mount options
ext4: replace MAX_DEFRAG_SIZE with EXT_MAX_BLOCK
ext4: Fix the alloc on close after a truncate hueristic
ext4: Add a tracepoint for ext4_alloc_da_blocks()
ext4: store EXT4_EXT_MIGRATE in i_state instead of i_flags
ext4: limit block allocations for indirect-block files to < 2^32
ext4: Fix different block exchange issue in EXT4_IOC_MOVE_EXT
ext4: Add null extent check to ext_get_path
ext4: Replace BUG_ON() with ext4_error() in move_extents.c
ext4: Replace get_ext_path macro with an inline funciton
ext4: Fix include/trace/events/ext4.h to work with Systemtap
ext4: Fix initalization of s_flex_groups
ext4: Always set dx_node's fake_dirent explicitly.
ext4: Fix async commit mode to be safe by using a barrier
ext4: Don't update superblock write time when filesystem is read-only
ext4: Clarify the locking details in mballoc
ext4: check for need init flag in ext4_mb_load_buddy
ext4: move ext4_mb_init_group() function earlier in the mballoc.c
ext4: Make non-journal fsync work properly
ext4: Assure that metadata blocks are written during fsync in no journal mode
...
Remove net/genetlink.h inclusion, now sched.c won't be recompiled
because of some networking changes.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow the short description after symbol name and dash in a kernel-doc
comment to span multiple lines, e.g. like this:
/**
* unmap_mapping_range - unmap the portion of all mmaps in the
* specified address_space corresponding to the specified
* page range in the underlying file.
* @mapping: the address space containing mmaps to be unmapped.
* ...
*/
The short description ends with a parameter description, an empty line
or the end of the comment block.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'current' is a pointer, so the right form is 'down_write(¤t->mm->mmap_sem)'.
Signed-off-by: Jianjun Kong <jianjun@zeuux.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kref_put() already occurs after the out label
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
[WATCHDOG] sizeof cleanup
[WATCHDOG] wdt_pci: fix printk and variable type
[WATCHDOG] wdt_pci - use pci_request_region
[WATCHDOG] ar7_wdt: Fix error handling during probe.
[WATCHDOG] ar7_wdt: convert to become a platform driver
[WATCHDOG] fix book E watchdog to take WDIOC_SETTIMEOUT arg in seconds
[WATCHDOG] davinci: use clock framework for timer frequency
[WATCHDOG] Use DIV_ROUND_UP() macro in the coh901327 WDT
[WATCHDOG] Add support for WM831x watchdog
[WATCHDOG] Add watchdog driver for NUC900
[WATCHDOG] add SBC-FITPC2 watchdog driver
* 'for-linus' of git://gitserver.sunplusct.com/linux-2.6-score: (22 commits)
score: add TIF_NOTIFY_RESUME define in asm/thread_info.h
score: make init_thread_union align to THREAD_SIZE
score: update files according to review comments.
score: add old syscall support
score: add MEMORY_START and MEMORY_SIZE define, to make the code clear
score: update inconsistent declare after .c was changed
score: remove unused code, add include files in .c
score: clean up mm/init.c
score: make irq.h definitions local
score: cleanups: dead code, 0 as pointer, shadowed variables
score: fix function prototypes
score: add address space annotations
score: add missing #includes
score: move save arg5 and arg6 instruction in front of enable_irq
score: add prototypes for wrapped syscalls
score: remove init_mm
score: add generic sys_call_table
score: remove __{put,get}_user_unknown
score: unset __ARCH_WANT_IPC_PARSE_VERSION
score: update files according to review comments
...
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (262 commits)
sh: mach-ecovec24: Add user debug switch support
sh: Kill off unused se_skipped in alignment trap notification code.
sh: Wire up HAVE_SYSCALL_TRACEPOINTS.
video: sh_mobile_lcdcfb: use both register sets for display panning
video: sh_mobile_lcdcfb: implement display panning
sh: Fix up sh7705 flush_dcache_page() build.
sh: kfr2r09: document the PLL/FLL <-> RF relationship.
sh: mach-ecovec24: need asm/clock.h.
sh: mach-ecovec24: deassert usb irq on boot.
sh: Add KEYSC support for EcoVec24
sh: add kycr2_delay for sh_keysc
sh: cpufreq: Include CPU id in info messages.
sh: multi-evt support for SH-X3 proto CPU.
sh: clkfwk: remove bogus set_bus_parent() from SH7709.
sh: Fix the indication point of the liquid crystal of AP-325RXA(AP3300)
sh: Add EcoVec24 romImage defconfig
sh: USB disable process is needed if romImage boot for EcoVec24
sh: EcoVec24: add HIZA setting for LED
sh: EcoVec24: write MAC address in boot
sh: Add romImage support for EcoVec24
...
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] Clean up linker script using standard macros.
[IA64] Use standard macros for page-aligned data.
[IA64] Use .ref.text, not .text.init for start_ap.
[IA64] sgi-xp: fix printk format warnings
[IA64] ioc4_serial: fix printk format warnings
[IA64] mbcs: fix printk format warnings
[IA64] pci_br, fix infinite loop in find_free_ate()
[IA64] kdump: Short path to freeze CPUs
[IA64] kdump: Try INIT regardless of
[IA64] kdump: Mask INIT first in panic-kdump path
[IA64] kdump: Don't return APs to SAL from kdump
[IA64] kexec: Unregister MCA handler before kexec
[IA64] kexec: Make INIT safe while transition to
[IA64] kdump: Mask MCA/INIT on frozen cpus
Fix up conflict in arch/ia64/kernel/vmlinux.lds.S as per Tony's
suggestion.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: add fusectl interface to max_background
fuse: limit user-specified values of max background requests
fuse: use drop_nlink() instead of direct nlink manipulation
fuse: document protocol version negotiation
fuse: make the number of max background requests and congestion threshold tunable
* 'davinci-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci: (62 commits)
DaVinci: DM646x - platform changes for vpif capture and display drivers
davinci: DM355 - platform changes for vpfe capture
davinci: DM644x platform changes for vpfe capture
davinci: audio: move tlv320aic33 i2c setup into board files
DaVinci: EDMA: Adding 2 new APIs for allocating/freeing PARAMs
DaVinci: DM365: Adding entries for DM365 IRQ's
DaVinci: DM355: Adding PINMUX entries for DM355 Display
davinci: Handle pinmux conflict between mmc/sd and nor flash
davinci: Add NOR flash support for da850/omap-l138
davinci: Add NAND flash support for DA850/OMAP-L138
davinci: Add MMC/SD support for da850/omap-l138
davinci: Add platform support for da850/omap-l138 GLCD
davinci: Macro to convert GPIO signal to GPIO pin number
davinci: Audio support for DA850/OMAP-L138 EVM
davinci: Audio support for DA830 EVM
davinci: Correct the number of GPIO pins for da850/omap-l138
davinci: Configure MDIO pins for EMAC
DaVinci: DM365: Add Support for new Revision of silicon
DaVinci: DM365: Fix Compilation issue due to PINMUX entry
DaVinci: EDMA: Updating default queue handling
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
dlm: use kernel_sendpage
dlm: fix connection close handling
dlm: fix double-release of socket in error exit path
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
ext3: Flush disk caches on fsync when needed
ext3: Add locking to ext3_do_update_inode
ext3: Fix possible deadlock between ext3_truncate() and ext3_get_blocks()
jbd: Annotate transaction start also for journal_restart()
jbd: Journal block numbers can ever be only 32-bit use unsigned int for them
ext3: Update MAINTAINERS for ext3 and JBD
JBD: round commit timer up to avoid uncommitted transaction
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ] Fix NULL ptr regression in powernow-k8
[CPUFREQ] Create a blacklist for processors that should not load the acpi-cpufreq module.
[CPUFREQ] Powernow-k8: Enable more than 2 low P-states
[CPUFREQ] remove rwsem lock from CPUFREQ_GOV_STOP call (second call site)
[CPUFREQ] ondemand - Use global sysfs dir for tuning settings
[CPUFREQ] Introduce global, not per core: /sys/devices/system/cpu/cpufreq
[CPUFREQ] Bail out of cpufreq_add_dev if the link for a managed CPU got created
[CPUFREQ] Factor out policy setting from cpufreq_add_dev
[CPUFREQ] Factor out interface creation from cpufreq_add_dev
[CPUFREQ] Factor out symlink creation from cpufreq_add_dev
[CPUFREQ] cleanup up -ENOMEM handling in cpufreq_add_dev
[CPUFREQ] Reduce scope of cpu_sys_dev in cpufreq_add_dev
[CPUFREQ] update Doc for cpuinfo_cur_freq and scaling_cur_freq
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (34 commits)
time: Prevent 32 bit overflow with set_normalized_timespec()
clocksource: Delay clocksource down rating to late boot
clocksource: clocksource_select must be called with mutex locked
clocksource: Resolve cpu hotplug dead lock with TSC unstable, fix crash
timers: Drop a function prototype
clocksource: Resolve cpu hotplug dead lock with TSC unstable
timer.c: Fix S/390 comments
timekeeping: Fix invalid getboottime() value
timekeeping: Fix up read_persistent_clock() breakage on sh
timekeeping: Increase granularity of read_persistent_clock(), build fix
time: Introduce CLOCK_REALTIME_COARSE
x86: Do not unregister PIT clocksource on PIT oneshot setup/shutdown
clocksource: Avoid clocksource watchdog circular locking dependency
clocksource: Protect the watchdog rating changes with clocksource_mutex
clocksource: Call clocksource_change_rating() outside of watchdog_lock
timekeeping: Introduce read_boot_clock
timekeeping: Increase granularity of read_persistent_clock()
timekeeping: Update clocksource with stop_machine
timekeeping: Add timekeeper read_clock helper functions
timekeeping: Move NTP adjusted clock multiplier to struct timekeeper
...
Fix trivial conflict due to MIPS lemote -> loongson renaming.
Commit ac89a9174 ("pty: don't limit the writes to 'pty_space()' inside
'pty_write()'") removed the pty_space() checking, in order to let the
regular tty buffer code limit the buffering itself.
That was all good, but as a subtle side effect it meant that we'd be
doing a tty_wakeup() even in the case where the buffers were all filled
up, and didn't actually make any progress on the write.
Which sounds innocuous, but it interacts very badly with the ppp_async
code, which has an infinite loop in ppp_async_push() that tries to push
out data to the tty. When we call tty_wakeup(), that loop ends up
thinking that progress was made (see the subtle interactions between
XMIT_WAKEUP and 'tty_stuffed' for details). End result: one unhappy ppp
user.
Fixed by noticing when tty_insert_flip_string() didn't actually do
anything, and then not doing any more processing (including, very much
not calling tty_wakeup()).
Bisected-and-tested-by: Peter Volkov <pva@gentoo.org>
Cc: stable@kernel.org (2.6.31)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
