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
a88a69c912,
'n_tty: Fix loss of echoed characters and remove bkl from n_tty'
and later in commit 38db89799b,
'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>
fix typo error introduced by commit ea0e6276 (usb: gadget: add
multiple definition guards) which causes the following build warning:
warning: "pr_vdebug" redefined
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Here's the big tty/serial driver patches for 3.9-rc1.
More tty port rework and fixes from Jiri here, as well as lots of
individual serial driver updates and fixes.
All of these have been in the linux-next tree for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)
iEYEABECAAYFAlEmZYQACgkQMUfUDdst+ylJDgCg0B0nMevUUdM4hLvxunbbiyXM
HUEAoIOedqriNNPvX4Bwy0hjeOEaWx0g
=vi6x
-----END PGP SIGNATURE-----
Merge tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial patches from Greg Kroah-Hartman:
"Here's the big tty/serial driver patches for 3.9-rc1.
More tty port rework and fixes from Jiri here, as well as lots of
individual serial driver updates and fixes.
All of these have been in the linux-next tree for a while."
* tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
tty: mxser: improve error handling in mxser_probe() and mxser_module_init()
serial: imx: fix uninitialized variable warning
serial: tegra: assume CONFIG_OF
TTY: do not update atime/mtime on read/write
lguest: select CONFIG_TTY to build properly.
ARM defconfigs: add missing inclusions of linux/platform_device.h
fb/exynos: include platform_device.h
ARM: sa1100/assabet: include platform_device.h directly
serial: imx: Fix recursive locking bug
pps: Fix build breakage from decoupling pps from tty
tty: Remove ancient hardpps()
pps: Additional cleanups in uart_handle_dcd_change
pps: Move timestamp read into PPS code proper
pps: Don't crash the machine when exiting will do
pps: Fix a use-after free bug when unregistering a source.
pps: Use pps_lookup_dev to reduce ldisc coupling
pps: Add pps_lookup_dev() function
tty: serial: uartlite: Support uartlite on big and little endian systems
tty: serial: uartlite: Fix sparse and checkpatch warnings
serial/arc-uart: Miscll DT related updates (Grant's review comments)
...
Fix up trivial conflicts, mostly just due to the TTY config option
clashing with the EXPERIMENTAL removal.
finally getting rid of the old ->start()/->stop() methods
in favor of the better and improved ->udc_start()/->udc_stop().
There were surprisingly quite a few users left, but all of them
have been converted.
f_mass_storage removed some dead code, which is always great ;-)
There's also a big cleanup to the gadget framework from Sebastian
which gets us a lot closer to having only function drivers in
kernel and move over to configfs-based binding.
Other than these, there's the usual set of cleanups: s3c UDCs are
moving over to devm_regulator_bulk_get() API, at91_udc removed
an unnecessary check for work_pending() before scheduling and
there's the removal of an unused variable from uac2_pcm_trigger().
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=PCP4
-----END PGP SIGNATURE-----
Merge tag 'gadget-for-v3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next
Felipe writes:
usb: gadget: patches for v3.9 merge window
finally getting rid of the old ->start()/->stop() methods
in favor of the better and improved ->udc_start()/->udc_stop().
There were surprisingly quite a few users left, but all of them
have been converted.
f_mass_storage removed some dead code, which is always great ;-)
There's also a big cleanup to the gadget framework from Sebastian
which gets us a lot closer to having only function drivers in
kernel and move over to configfs-based binding.
Other than these, there's the usual set of cleanups: s3c UDCs are
moving over to devm_regulator_bulk_get() API, at91_udc removed
an unnecessary check for work_pending() before scheduling and
there's the removal of an unused variable from uac2_pcm_trigger().
drivers/usb/gadget/u_serial.c:1291:5: sparse: symbol \
'userial_init' was not declared. Should it be static?
drivers/usb/gadget/zero.c:66:25: sparse: symbol \
'gzero_options' was not declared. Should it be static?
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This patch removes gserial_setup() and gserial_cleanup() and adds
gserial_alloc_line() and gserial_free_line() to replace them.
The initial setup of u_serial happens now on module load time. A
maximum of four TTY ports can be requested which is the current limit.
In theory we could extend this limit, the hard limit is the number of
available endpoints.
alloc_tty_driver() is now called at module init time with the max
available ports. The per-line footprint here is on 32bit is 3 * size of
pointer + 60 bytes (for cdevs).
The remaining memory (struct gs_port) is allocated once a port is
requested.
With this change it is possible to load g_multi and g_serial at the same
time. GS0 receives the module that is loaded first, GS1 is received by
the next module and so on. With the configfs interface the port number
can be exported and the device node is more predictable. Nothing changes
for g_serial and friends as long as one module is used.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Every user of u_serial has now to select the U_SERIAL symbol instead of
including the file.
There is one limition with this: ports and and gs_tty_driver are global
variables in u_serial. Since all users share them, there can be only one
user loaded at a time i.e. either g_serial or g_nokia.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
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>
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>
When a device is switched off by software, gserial_cleanup will
be called, and switch off will be blocked in this function
because wake_up_interruptible() in gs_close() can not wake_up
the wait_event() in gserial_cleanup(), it should be changed to
wake_up() to match the wait_event().
Signed-off-by: Haipeng YU <haipeng.yu@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
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>
If f_fs.c and u_serial.c are combined together using #include, which has
been a common practice so far, the pr_vdebug macro is defined multiple
times. Define it only once.
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
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>
Pull trivial updates from Jiri Kosina:
"As usual, it's mostly typo fixes, redundant code elimination and some
documentation updates."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (57 commits)
edac, mips: don't change code that has been removed in edac/mips tree
xtensa: Change mail addresses of Hannes Weiner and Oskar Schirmer
lib: Change mail address of Oskar Schirmer
net: Change mail address of Oskar Schirmer
arm/m68k: Change mail address of Sebastian Hess
i2c: Change mail address of Oskar Schirmer
net: Fix tcp_build_and_update_options comment in struct tcp_sock
atomic64_32.h: fix parameter naming mismatch
Kconfig: replace "--- help ---" with "---help---"
c2port: fix bogus Kconfig "default no"
edac: Fix spelling errors.
qla1280: Remove redundant NULL check before release_firmware() call
remoteproc: remove redundant NULL check before release_firmware()
qla2xxx: Remove redundant NULL check before release_firmware() call.
aic94xx: Get rid of redundant NULL check before release_firmware() call
tehuti: delete redundant NULL check before release_firmware()
qlogic: get rid of a redundant test for NULL before call to release_firmware()
bna: remove redundant NULL test before release_firmware()
tg3: remove redundant NULL test before release_firmware() call
typhoon: get rid of redundant conditional before all to release_firmware()
...
Here's the big TTY/serial driver pull request for the 3.5-rc1 merge window.
Nothing major in here, just lots of incremental changes from Alan and
Jiri reworking some tty core things to behave better and to get a more
solid grasp on some of the nasty tty locking issues.
There are a few tty and serial driver updates in here as well.
All of this has been in the linux-next releases for a while with no problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (GNU/Linux)
iEYEABECAAYFAk+7rBoACgkQMUfUDdst+ykXsgCfeDKx6ZgLidYy3H40Y2Pt3XEO
TicAn1fcdGwOmMR/mowa+kTA68D/J6i2
=S7tG
-----END PGP SIGNATURE-----
Merge tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull TTY updates from Greg Kroah-Hartman:
"Here's the big TTY/serial driver pull request for the 3.5-rc1 merge
window.
Nothing major in here, just lots of incremental changes from Alan and
Jiri reworking some tty core things to behave better and to get a more
solid grasp on some of the nasty tty locking issues.
There are a few tty and serial driver updates in here as well.
All of this has been in the linux-next releases for a while with no
problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'tty-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (115 commits)
serial: bfin_uart: Make MMR access compatible with 32 bits bf609 style controller.
serial: bfin_uart: RTS and CTS MMRs can be either 16-bit width or 32-bit width.
serial: bfin_uart: narrow the reboot condition in DMA tx interrupt
serial: bfin_uart: Adapt bf5xx serial driver to bf60x serial4 controller.
Revert "serial_core: Update buffer overrun statistics."
tty: hvc_xen: NULL dereference on allocation failure
tty: Fix LED error return
tty: Allow uart_register/unregister/register
tty: move global ldisc idle waitqueue to the individual ldisc
serial8250-em: Add DT support
serial8250-em: clk_get() IS_ERR() error handling fix
serial_core: Update buffer overrun statistics.
tty: drop the pty lock during hangup
cris: fix missing tty arg in wait_event_interruptible_tty call
tty/amiserial: Add missing argument for tty_unlock()
tty_lock: Localise the lock
pty: Lock the devpts bits privately
tty_lock: undo the old tty_lock use on the ctty
serial8250-em: Emma Mobile UART driver V2
Add missing call to uart_update_timeout()
...
Remove geserial_setup from the init section. The android gadget
driver calls it after probe, after userspace has configured the
gadget driver.
Signed-off-by: Benoit Goby <benoit@android.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge with latest Linus' tree, as I have incoming patches
that fix code that is newer than current HEAD of for-next.
Conflicts:
drivers/net/ethernet/realtek/r8169.c
Emit the function name not the address when possible.
builtin_return_address() gives an address. When building
a kernel with CONFIG_KALLSYMS, emit the actual function
name not the address.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Checking if tty->index is in bounds is not needed. The tty has the
index set in the initial open. This is done in get_tty_driver. And it
can be only in interval <0,driver->num).
So remove the tests which check exactly this interval. Some are
left untouched as they check against the current backing device count.
(Leaving apart that the check is racy in most of the cases.)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
With module.h being implicitly everywhere via device.h, the absence
of explicitly including something for EXPORT_SYMBOL went unnoticed.
Since we are heading to fix things up and clean module.h from the
device.h file, we need to explicitly include these files now.
Use the lightweight version of the header that has just THIS_MODULE
and EXPORT_SYMBOL variants.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Change usb_ep_enable() prototype to use endpoint
descriptor from usb_ep.
This optimization spares the FDs from saving the
endpoint chosen descriptor. This optimization is
not full though. To fully exploit this change, one
needs to update all the UDCs as well since in the
current implementation each of them saves the
endpoint descriptor in it's internal (and extended)
endpoint structure.
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
OK, the USB gadget serial driver actually has a couple of problems. On
gs_open(), it always allocates and queues an additional QUEUE_SIZE (16)
worth of requests, so with a loop like this:
i=1 ; while echo $i > /dev/ttyGS0 ; do let i++ ; done
eventually we run into OOM (Out of Memory).
Technically, it is not a leak as everything gets freed up when the USB
connection is broken, but not on gs_close().
With a USB device/gadget controller driver that has limited resources
(e.g., Marvell has a this MAX_XDS_FOR_TR_CALLS of 64 for transmit and
receive), so even after 4
stty -F /dev/ttyGS0
we cannot transmit anymore. We can still receive (not necessarily
reliably) as now we have 16 * 4 = 64 descriptors/buffers ready, but the
device is otherwise not usable.
Signed-off-by: Jim Sung <jsung@syncadence.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Here is the patch for the following issue:
drivers/usb/gadget/u_serial.c: In function ‘gs_start_tx’:
drivers/usb/gadget/u_serial.c:369: error: ‘TASK_INTERRUPTIBLE’ undeclared (first use in this function)
drivers/usb/gadget/u_serial.c:369: error: (Each undeclared identifier is reported only once
drivers/usb/gadget/u_serial.c:369: error: for each function it appears in.)
drivers/usb/gadget/u_serial.c: In function ‘gs_rx_push’:
drivers/usb/gadget/u_serial.c:546: error: ‘TASK_INTERRUPTIBLE’ undeclared (first use in this function)
drivers/usb/gadget/u_serial.c: In function ‘gs_close’:
drivers/usb/gadget/u_serial.c:857: error: ‘TASK_INTERRUPTIBLE’ undeclared (first use in this function)
drivers/usb/gadget/u_serial.c:857: error: implicit declaration of function ‘signal_pending’
drivers/usb/gadget/u_serial.c:857: error: implicit declaration of function ‘schedule_timeout’
drivers/usb/gadget/u_serial.c: In function ‘gserial_cleanup’:
drivers/usb/gadget/u_serial.c:1190: error: ‘TASK_UNINTERRUPTIBLE’ undeclared (first use in this function)
drivers/usb/gadget/u_serial.c:1190: error: implicit declaration of function ‘schedule’
drivers/usb/gadget/u_serial.c: In function ‘gserial_disconnect’:
drivers/usb/gadget/u_serial.c:1311: error: ‘TASK_INTERRUPTIBLE’ undeclared (first use in this function)
Signed-off-by: Stephane Duverger <stephane.duverger@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Call put_tty_driver() in cleanup function, to fix Oops when trying to open
gadget serial char device after module unload.
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
No longer set low_latency flag as it causes this warning backtrace:
WARNING: at kernel/mutex.c:207 __mutex_lock_slowpath+0x6c/0x288()
Fix associated locking and wakeups.
Signed-off-by: Jon Povey <jon.povey@racelogic.co.uk>
Cc: Maulik Mankad <x0082077@ti.com>
Cc: stable <stable@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
If the driver cannot be registered, put_tty_driver(gs_tty_driver)
occurred here as well as at label fail.
put_tty_driver() already occurs at label fail
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some usb serial host drivers expect a short packet before they forward
the data to the application. This is caused by them trying to read more
than one packet at a time. So when the gadget sends an exact multiple
of the maximum packet size, it should append a zero-length packet.
Signed-off-by: Daniel Glöckner <dg@emlix.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The base versions handle constant folding now.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Update the CDC-ACM gadget code to support the peripheral-to-host
notifications when the tty is opened or closed, or issues a BREAK.
The serial framework code calls new generic hooks; right now only
CDC-ACM uses those hooks. This resolves several REVISIT comments
in the code. (Based on a patch from Felipe Balbi.)
Note that this doesn't expose USB_CDC_CAP_BRK to the host, since
this code still rejects USB_CDC_REQ_SEND_BREAK control requests
for host-to-peripheral BREAK signaling (received via /dev/ttyGS*).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Update RX path handling in new serial gadget code to cope better with
RX blockage: queue every RX packet until its contents can safely be
passed up to the ldisc. Most of the RX path work is now done in the
RX tasklet, instead of just the final "push to ldisc" step. This
addresses some cases of data loss:
- A longstanding serial gadget bug: when tty_insert_flip_string()
didn't copy the entire buffer, the rest of the characters were
dropped! Now that packet stays queued until the rest of its data
is pushed to the ldisc.
- Another longstanding issue: in the unlikely case that an RX
transfer returns data and also reports a fault, that data is
no longer discarded.
- In the recently added RX throttling logic: it needs to stop
pushing data into the TTY layer, instead of just not submitting
new USB read requests. When the TTY is throttled long enough,
backpressure will eventually make the OUT endpoint NAK.
Also: an #ifdef is removed (no longer necessary); and start switching
to a better convention for debug messages (prefix them with tty name).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These two fixes ensure the new "CDC Composite Device" gadget
fails cleanly when it's loaded on hardware that can't support
this particular gadget driver.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This abstracts the "gadget serial" driver TTY glue into a separate
component, cleaning it up and disentangling it from connection state.
It also changed some behaviors for the better:
- Stops using "experimental" major #127, and switches over to
having the TTY layer allocate the dev_t numbers.
- Provides /sys/class/tty/ttyGS* nodes, thus mdev/udev support.
(Note "mdev" hotplug bug in Busybox v1.7.2: /dev/ttyGS0 will
be a *block* device without CONFIG_SYSFS_DEPRECATED_V2.)
- The tty nodes no longer reject opens when there's no host.
Now they can support normal getty configs in /etc/inttab...
- Now implements RX throttling. When the line discipline says
it doesn't want any more data, only packets in flight will be
delivered (currently, max 1K/8K at full/high speeds) until it
unthrottles the data.
- Supports low_latency. This is a good policy for all USB serial
adapters, since it eliminates scheduler overhead on RX paths.
This also includes much cleanup including better comments, fixing
memory leaks and other bugs (including some locking fixes), messaging
cleanup, and an interface audit and tightening. This added up to a
significant object code shrinkage, on the order of 20% (!) depending
on CPU and compiler.
A separate patch actually kicks in this new code, using the functions
declared in this new header, and removes the previous glue.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
