It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.
Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.
This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a calc_num_ports callback to the generic driver and verify that the
device has the required endpoints there instead of in core.
Note that the generic driver num_ports field was never used.
Signed-off-by: Johan Hovold <johan@kernel.org>
Allow subdrivers to modify the port-endpoint mapping by passing the
endpoint descriptors to calc_num_ports.
The callback can now also be used to verify that the required endpoints
exists and abort probing otherwise.
This will allow us to get rid of a few hacks in subdrivers that are
already modifying the port-endpoint mapping (or aborting probe due to
missing endpoints), but only after the port structures have been setup.
Signed-off-by: Johan Hovold <johan@kernel.org>
Allow drivers to specify a minimum number of endpoints per type, which
USB serial core will verify after subdriver probe has returned (where
the current alternate setting may have been changed).
Signed-off-by: Johan Hovold <johan@kernel.org>
Raise the arbitrary limit of how many ports a single device can claim
from eight to 16.
This specifically enables the upper eight ports of some mxuport devices.
Signed-off-by: Johan Hovold <johan@kernel.org>
This reverts commit 5083fd7bdf.
A bulk-out size smaller than the end-point size is indeed valid. The
offending commit broke the usb-debug driver for EHCI debug devices,
which use 8-byte buffers.
Fixes: 5083fd7bdf ("USB: serial: make bulk_out_size a lower limit")
Reported-by: "Li, Elvin" <elvin.li@intel.com>
Cc: stable <stable@vger.kernel.org> # v3.15
Signed-off-by: Johan Hovold <johan@kernel.org>
Drivers are allowed to override the default bulk-out buffer size
(endpoint maximum packet size) in order to increase throughput, but it
does not make much sense to allow buffers smaller than the default.
Note that this is already how bulk_in_size is defined.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Export usb_serial_generic_write_start which is needed when implementing
a custom resume function while still relying on the generic write
implementation.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We had the limit of 255 USB to serial devices on one system for almost
15 years, with no complaints. But now it's time to move on from these
tiny "baby" systems, and bump the number up to 512, which should last
us a few more years:
"512 is a nice number" -- Tobias Winter
Note, this is still a static value, and uses up tty core memory with
this many tty devices allocated. Converting the driver to use
TTY_DRIVER_DYNAMIC_DEV is the next thing to do in order to remove this
limitation.
Reported-by: Tobias Winter <tobias@linuxdingsda.de>
Tested-by: Tobias Winter <tobias@linuxdingsda.de>
Reviewed-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This moves the allocation of minor device numbers from a static array to
be dynamic, using the idr interface. This means that you could
potentially get "gaps" in a minor number range for a single USB serial
device with multiple ports, but all should still work properly.
We remove the 'minor' field from the usb_serial structure, as it no
longer makes any sense for it (use the field in the usb_serial_port
structure if you really want to know this number), and take the fact
that we were overloading a number in this field to determine if we had
initialized the minor numbers or not, and just use a flag variable
instead.
Note, we still have the limitation of 255 USB to serial devices in the
system, as that is all we are registering with the TTY layer at this
point in time.
Tested-by: Tobias Winter <tobias@linuxdingsda.de>
Reviewed-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The usb_serial_port structure had the number field, which was the minor
number for the port, which almost no one really cared about. They
really wanted the number of the port within the device, which you had to
subtract from the minor of the parent usb_serial_device structure. To
clean this up, provide the real minor number of the port, and the number
of the port within the serial device separately, as these numbers might
not be related in the future.
Bonus is that this cleans up a lot of logic in the drivers, and saves
lines overall.
Tested-by: Tobias Winter <tobias@linuxdingsda.de>
Reviewed-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--
drivers/staging/serqt_usb2/serqt_usb2.c | 21 +++--------
drivers/usb/serial/ark3116.c | 2 -
drivers/usb/serial/bus.c | 6 +--
drivers/usb/serial/console.c | 2 -
drivers/usb/serial/cp210x.c | 2 -
drivers/usb/serial/cypress_m8.c | 4 +-
drivers/usb/serial/digi_acceleport.c | 6 ---
drivers/usb/serial/f81232.c | 5 +-
drivers/usb/serial/garmin_gps.c | 6 +--
drivers/usb/serial/io_edgeport.c | 58 ++++++++++++--------------------
drivers/usb/serial/io_ti.c | 21 ++++-------
drivers/usb/serial/keyspan.c | 29 +++++++---------
drivers/usb/serial/metro-usb.c | 4 +-
drivers/usb/serial/mos7720.c | 37 +++++++++-----------
drivers/usb/serial/mos7840.c | 52 +++++++++-------------------
drivers/usb/serial/opticon.c | 2 -
drivers/usb/serial/pl2303.c | 2 -
drivers/usb/serial/quatech2.c | 7 +--
drivers/usb/serial/sierra.c | 2 -
drivers/usb/serial/ti_usb_3410_5052.c | 10 ++---
drivers/usb/serial/usb-serial.c | 7 ++-
drivers/usb/serial/usb_wwan.c | 2 -
drivers/usb/serial/whiteheat.c | 20 +++++------
include/linux/usb/serial.h | 6 ++-
24 files changed, 133 insertions(+), 180 deletions(-)
Add generic wait_until_sent implementation which polls for empty
hardware buffers using the new port-operation tx_empty.
The generic implementation will be used for all sub-drivers that
implement tx_empty but does not define wait_until_sent.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add wait_until_sent operation which can be used to wait for hardware
buffers to drain.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove the port MSR-wait queue now that all drivers have been migrated
to the tty-port queue.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add generic get_icount implementation that subdrivers relying on the
port interrupt counters can use.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add generic TIOCMIWAIT implementation which correctly handles hangup,
USB-device disconnect, does not rely on the deprecated sleep_on
functions and hence does not suffer from the races currently affecting
several usb-serial drivers.
This makes it much easier to add TIOCMIWAIT support to subdrivers as the
tricky details related to hangup and disconnect (e.g. atomicity, that
the private port data may have been freed when woken up, and waking up
processes at disconnect) have been handled once and for all.
To add support to a subdriver, simply set the tiocmiwait-port-operation
field, update the port icount fields and wake up any process sleeping on
the tty-port modem-status-change wait queue on changes.
Note that the tty-port initialised flag can be used to detect
disconnected as the port will be hung up as part of disconnect (and
cannot be reactivated due to the disconnected flag). However, as the
tty-port implementation currently wakes up processes before calling port
shutdown, the tty-hupping flag must also be checked to detect hangup for
now.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove empty generic release implementation and make the release
callback non-mandatory (like attach, probe and disconnect).
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove the now empty generic disconnect callback and make the disconnect
callback non-mandatory.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add modem-status-change wait queue to struct usb_serial_port that
subdrivers can use to implement TIOCMIWAIT.
Currently subdrivers use a private wait queue which may have been
released when waking up after device disconnected.
Note that we're adding a new wait queue rather than reusing the tty-port
one as we do not want to get woken up at hangup (yet).
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This Patch adds support for the newer Cypress FX2LP. It also adapts
three drivers currently using ezusb to the interface change. (whiteheat
and keyspan[_pda])
Signed-off-by: René Bürgel <rene.buergel@sohard.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that all usb-serial modules are only using dev_dbg()
the debug module parameter does not do anything at all, so
remove it to reduce any confusion if someone were to try
to use it.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should use dev_dbg() for usb_serial_debug_data() like all of the rest
of the usb-serial drivers use, so remove the debug parameter as it's not
needed.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that all in-kernel users of the dbg() macro are gone, we can remove
it from the include/linux/usb/serial.h file.
Good riddance.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes the dependency on the usb_serial interface and names
some magic constants
Signed-off-by: René Bürgel <rene.buergel@sohard.de>
--
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The callback is now hooked up for any USB to serial driver that wants
it. We only register the callback if any of the usb-serial structures
want it, this keeps the USB core happy.
Thanks to Alan Stern for the ideas on how to do this.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reworks the usb_serial_register_drivers() and
usb_serial_deregister_drivers() to not need a pointer to a struct
usb_driver anymore. The usb_driver structure is now created dynamically
and registered and unregistered as needed.
This saves lines of code in each usb-serial driver. All in-kernel users
of these functions were also fixed up at this time. The pl2303 driver
was tested that everything worked properly.
Thanks for the idea to do this from Alan Stern.
Cc: Adhir Ramjiawan <adhirramjiawan0@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Al Borchers <alborchers@steinerpoint.com>
Cc: Aleksey Babahin <tamerlan311@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Worsley <amworsley@gmail.com>
Cc: Bart Hartgers <bart.hartgers@gmail.com>
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Donald Lee <donald@asix.com.tw>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Gary Brubaker <xavyer@ix.netcom.com>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Julia Lawall <julia@diku.dk>
Cc: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Lonnie Mendez <dignome@gmail.com>
Cc: Matthias Bruestle and Harald Welte <support@reiner-sct.com>
Cc: Matthias Urlichs <smurf@smurf.noris.de>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Michal Sroczynski <msroczyn@gmail.com>
Cc: "Michał Wróbel" <michal.wrobel@flytronic.pl>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Berger <pberger@brimson.com>
Cc: Preston Fick <preston.fick@silabs.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Rigbert Hamisch <rigbert@gmx.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Simon Arlott <simon@fire.lp0.eu>
Cc: Support Department <support@connecttech.com>
Cc: Thomas Tuttle <ttuttle@chromium.org>
Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Cc: Wang YanQing <Udknight@gmail.com>
Cc: William Greathouse <wgreathouse@smva.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I can't remember why I wrote it like this many many years ago, but it's
not needed at all, let's rely on the usb-serial core for this function,
especially as it is being overridden by it anyway.
This lets us make usb_serial_probe() a static function, which it should
be.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is now set by the usb-serial core, no need for the driver to
individually set it.
Thanks to Alan Stern for the idea to get rid of it.
Cc: William Greathouse <wgreathouse@smva.com>
Cc: Matthias Bruestle and Harald Welte <support@reiner-sct.com>
Cc: Lonnie Mendez <dignome@gmail.com>
Cc: Peter Berger <pberger@brimson.com>
Cc: Al Borchers <alborchers@steinerpoint.com>
Cc: Gary Brubaker <xavyer@ix.netcom.com>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: Matthias Urlichs <smurf@smurf.noris.de>
Cc: Support Department <support@connecttech.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Kautuk Consul <consul.kautuk@gmail.com>
Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Bart Hartgers <bart.hartgers@gmail.com>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Preston Fick <preston.fick@silabs.com>
Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Cc: Simon Arlott <simon@fire.lp0.eu>
Cc: Andrew Worsley <amworsley@gmail.com>
Cc: "Michał Wróbel" <michal.wrobel@flytronic.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Aleksey Babahin <tamerlan311@gmail.com>
Cc: Dan Carpenter <error27@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Donald Lee <donald@asix.com.tw>
Cc: Julia Lawall <julia@diku.dk>
Cc: Michal Sroczynski <msroczyn@gmail.com>
Cc: Wang YanQing <Udknight@gmail.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Thomas Tuttle <ttuttle@chromium.org>
Cc: Rigbert Hamisch <rigbert@gmx.de>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Adhir Ramjiawan <adhirramjiawan0@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1536) fixes a bug in the USB serial core. Unloading and
reloading a serial driver while a serial device is plugged in causes
errors because of the code in usb_serial_disconnect() that tries to
make sure the port_remove method is called. With the new order of
driver registration introduced in the 3.4 kernel, this is definitely
not the right thing to do (if indeed it ever was).
The patch removes that whole section code, along with the mechanism
for keeping track of each port's registration state, which is no
longer needed. The driver core can handle all that stuff for us.
Note: This has been tested only with one or two USB serial drivers.
In theory, other drivers might still run into trouble. But if they
do, it will be the fault of the drivers, not of this patch -- that is,
the drivers will need to be fixed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that module_driver() can handle varargs, use it instead of rolling
our own version.
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that Alan Stern has cleaned up the usb serial driver registration,
we have the ability to create a module_usb_serial_driver macro to make
things a bit simpler, like the other *_driver macros created.
But, as we need two functions here, we can't reuse the existing
module_driver() macro, so we need to roll our own.
Here's a patch implementing module_usb_serial_driver() and it converts
the pl2303 driver to use it, showing a nice cleanup.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No one uses them anymore, they should be using the safer
usb_serial_register_drivers() and usb_serial_deregister_drivers()
functions instead.
Thanks to Alan Stern for writing these functions and porting all
in-kernel users to them.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1522) adds two new routines to the usb-serial core, for
registering and unregistering serial drivers. Instead of registering
the usb_driver and usb_serial_drivers separately, with error checking
for each one, the drivers can all be registered and unregistered by a
single function call. This reduces duplicated code.
More importantly, the new core routines change the order in which the
drivers are registered. Currently the usb-serial drivers are all
registered first and the usb_driver is done last, which leaves a
window for problems. A udev script may quickly add a new dynamic-ID
for a usb-serial driver, causing the corresponding usb_driver to be
probed. If the usb_driver hasn't been registered yet then an oops
will occur.
The new routine prevents such problems by registering the usb_driver
first. To insure that it gets probed properly for already-attached
serial devices, we call driver_attach() after all the usb-serial
drivers have been registered.
Along with adding the new routines, the patch modifies the "generic"
serial driver to use them. Further patches will similarly modify all
the other in-tree USB serial drivers.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add macro which prints an error message only once if port is used a
console.
Reporting errors in a write path when port is used as a console could
otherwise result in an infinite loop.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for multiple read urbs to generic read implementation.
Use a static array of two read urbs for now which is enough to get a
50% throughput increase in one test setup.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove no longer used write_urb_busy field from struct usb_serial_port.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (76 commits)
pch_uart: reference clock on CM-iTC
pch_phub: add new device ML7213
n_gsm: fix UIH control byte : P bit should be 0
n_gsm: add a documentation
serial: msm_serial_hs: Add MSM high speed UART driver
tty_audit: fix tty_audit_add_data live lock on audit disabled
tty: move cd1865.h to drivers/staging/tty/
Staging: tty: fix build with epca.c driver
pcmcia: synclink_cs: fix prototype for mgslpc_ioctl()
Staging: generic_serial: fix double locking bug
nozomi: don't use flush_scheduled_work()
tty/serial: Relax the device_type restriction from of_serial
MAINTAINERS: Update HVC file patterns
tty: phase out of ioctl file pointer for tty3270 as well
tty: forgot to remove ipwireless from drivers/char/pcmcia/Makefile
pch_uart: Fix DMA channel miss-setting issue.
pch_uart: fix exclusive access issue
pch_uart: fix auto flow control miss-setting issue
pch_uart: fix uart clock setting issue
pch_uart : Use dev_xxx not pr_xxx
...
Fix up trivial conflicts in drivers/misc/pch_phub.c (same patch applied
twice, then changes to the same area in one branch)
When a driver doesn't know how much data a device is going to send,
the buffer size should be at least as big as the endpoint's maxpacket
value. The serial drivers don't follow this rule; many of them
request only 256-byte bulk-in buffers. As a result, they suffer
overflow errors if a high-speed device wants to send a lot of data,
because high-speed bulk endpoints are required to have a maxpacket
size of 512.
This patch (as1450) fixes the problem by using the driver's
bulk_in_size value as a minimum, always allocating buffers no smaller
than the endpoint's maxpacket size.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Flynn Marquardt <flynn@flynnux.de>
CC: <stable@kernel.org> [after .39-rc1 is out]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't use it so we can trim it from here as we try and stamp the file
object dependencies out of the serial code.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Doing tiocmget was such fun we should do tiocmset as well for the same
reasons
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Alan's commit 335f8514f2 introduced
.carrier_raised function in several drivers. That also means
tty_port_block_til_ready can now suspend the process trying to open the serial
port when Carrier Detect is low and put it into tty_port.open_wait queue. We
need to wake up the process when Carrier Detect goes high and trigger TTY
hangup when CD goes low.
Some of the devices do not report modem status line changes, or at least we
don't understand the status message, so for those we remove .carrier_raised
again.
Signed-off-by: Libor Pechacek <lpechacek@suse.cz>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.
This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since handle_sysrq() does not take tty as argument anymore we can
drop it from usb_serial_handle_sysrq_char() as well.
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Remove multi-urb write from the generic driver and simplify the
prepare_write_buffer prototype:
int (*prepare_write_buffer)(struct usb_serial_port *port,
void *dest, size_t size);
The default implementation simply fills dest with data from port write
fifo but drivers can override it if they need to process the outgoing
data (e.g. add headers).
Turn ftdi_sio into a generic fifo-based driver, which lowers CPU usage
significantly for small writes while retaining maximum throughput.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Reimplement fifo-based writes in the generic driver using a multiple
pre-allocated urb scheme.
In contrast to multi-urb writes, no allocations (of urbs or buffers) are
made during run-time and there is less pressure on the host stack
queues as currently only two urbs are used (implementation is generic
and can handle more than two urbs as well, though).
Initial tests using ftdi_sio show that the implementation achieves the
same (maximum) throughput at high baudrates as multi-urb writes. The CPU
usage is much lower than for multi-urb writes for small write requests
and only slightly higher for large (e.g. 2k) requests (due to extra copy
via fifo?).
Also outperforms multi-urb writes for small write requests on an
embedded arm-9 system, where multi-urb writes are CPU-bound at high
baudrates (perf reveals that a lot of time is spent in the host stack
enqueue function -- could perhaps be a bug as well).
Keeping the original write_urb, buffer and flag for now as there are
other drivers depending on them.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Greg Kroah-Hartman