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* USB: serial: fix write memory-allocation flagJohan Hovold2013-11-251-1/+1
| | | | | | | | | | | | Fix regression introduced by commit 818f60365a29 ("USB: serial: add memory flags to usb_serial_generic_write_start"), which incorrectly used GFP_KERNEL in write(), which must not not sleep. Reported-by: Dave Jones <davej@fedoraproject.org> Tested-by: Dave Jones <davej@fedoraproject.org> Cc: Dave Jones <davej@fedoraproject.org> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: fix race in generic writeJohan Hovold2013-11-251-9/+1
| | | | | | | | | | | | | | | | | | | Fix race in generic write implementation, which could lead to temporarily degraded throughput. The current generic write implementation introduced by commit 27c7acf22047 ("USB: serial: reimplement generic fifo-based writes") has always had this bug, although it's fairly hard to trigger and the consequences are not likely to be noticed. Specifically, a write() on one CPU while the completion handler is running on another could result in only one of the two write urbs being utilised to empty the remainder of the write fifo (unless there is a second write() that doesn't race during that time). Cc: stable <stable@vger.kernel.org> # 2.6.35 Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: export usb_serial_generic_write_startJohan Hovold2013-10-111-1/+2
| | | | | | | | | 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>
* USB: serial: add memory flags to usb_serial_generic_write_startJohan Hovold2013-10-111-8/+10
| | | | | | | | | | | | | Add memory-flags parameter to usb_serial_generic_write_start which is called from write, resume and completion handler, all with different allocation requirements. Note that by using the memory flag to determine when called from the completion handler, everything will work as before even if the completion handler is run with interrupts enabled (as suggested). Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: clean up comments in generic driverJohan Hovold2013-10-111-32/+25
| | | | | | | Clean up some comments, drop excessive comments and fix-up style. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: invoke dcd_change ldisc's handler.Paul Chavent2013-09-261-0/+10
| | | | | | | | | | | | | The DCD pin of the serial port can receive a PPS signal. By calling the port line discipline dcd handle, this patch allow to monitor PPS through USB serial devices. However the performance aren't as good as the uart drivers, so document this point too. Signed-off-by: Paul Chavent <paul.chavent@onera.fr> Acked-by: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: remove hupping check from tiocmiwaitJohan Hovold2013-07-231-11/+2
| | | | | | | | | Since commit 31ca020b ("TTY: wake up processes last at hangup") there no longer any need to check the hupping flag in the generic tiocmiwait implementation, so remove it. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: add generic wait_until_sent implementationJohan Hovold2013-05-161-0/+31
| | | | | | | | | | | 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>
* USB: serial: update copyright informationJohan Hovold2013-03-251-1/+1
| | | | | | | Update copyright information. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: add generic get_icount implementationJohan Hovold2013-03-251-0/+27
| | | | | | | | 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>
* USB: serial: add generic TIOCMIWAIT implementationJohan Hovold2013-03-251-0/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* USB: serial: remove generic release callbackJohan Hovold2013-03-251-5/+0
| | | | | | | | 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>
* USB: serial: remove generic disconnect callbackJohan Hovold2013-03-251-6/+0
| | | | | | | | 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>
* USB: serial: fix generic disconnect implementationJohan Hovold2013-03-251-11/+1
| | | | | | | | | There is no need for the generic disconnect callback to stop the read and write urbs a second time as this has already been taken care of by close (which is called from hangup as part of disconnect). Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: remove bogus disconnect test in cleanupJohan Hovold2013-03-251-14/+10
| | | | | | | | | | | Remove bogus (and unnecessary) test for serial->dev being NULL in cleanup. The device is never cleared, and cleanup is never called after a completed disconnect anyway. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: remove port number from generic-driver debugJohan Hovold2013-03-251-6/+4
| | | | | | | | Remove redundant port number from debug output (already printed as part of device name). Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* TTY: switch tty_flip_buffer_pushJiri Slaby2013-01-151-7/+1
| | | | | | | | | | | | | | | | | | | | 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>
* TTY: switch tty_insert_flip_stringJiri Slaby2013-01-151-1/+1
| | | | | | | | | | | | 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>
* TTY: switch tty_insert_flip_charJiri Slaby2013-01-151-1/+1
| | | | | | | | | | | | | 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>
* USB: serial: export usb_serial_generic_chars_in_bufferJohan Hovold2012-10-301-0/+1
| | | | | | | | Export generic chars_in_buffer implementation so it can be used in subdrivers in combination with checks of any hardware buffers. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: Serial: usb-serial: remove debug module parameterGreg Kroah-Hartman2012-09-181-4/+1
| | | | | | | | | 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>
* USB: serial: remove debug parameter from usb_serial_debug_data()Greg Kroah-Hartman2012-09-181-4/+2
| | | | | | | | 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>
* USB: serial-generic: use a single set of device IDsAlan Stern2012-06-131-8/+2
| | | | | | | | | | | | | | | | The usb-serial-generic driver uses different device IDs for its USB matching and its serial matching. This can lead to problems: The driver can end up getting bound to a USB interface without being allowed to bind to the corresponding serial port. This patch (as1557) fixes the problem by using the same device ID table (the one that can be altered by the "vendor=" and "product=" module parameters) for both purposes. The unused table is removed. Now the driver will bind only to the intended devices. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Bjørn Mork <bjorn@mork.no> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: generic.c: remove dbg() usageGreg Kroah-Hartman2012-05-151-8/+13
| | | | | | | | dbg() is a usb-serial specific macro. This patch converts the generic.c driver to use dev_dbg() instead to tie into the dynamic debug infrastructure. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: rework usb_serial_register/deregister_drivers()Greg Kroah-Hartman2012-05-081-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* USB: serial: remove bizarre generic_serial probe functionGreg Kroah-Hartman2012-05-071-14/+0
| | | | | | | | | | | | 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>
* USB: serial: remove usb_serial_disconnect call in all driversGreg Kroah-Hartman2012-05-071-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* USB: generic.c: remove dbg() tracing callsGreg Kroah-Hartman2012-05-031-22/+0
| | | | | | | dbg() was used a lot a long time ago to trace code flow. Now that we have ftrace, this isn't needed at all, so remove these calls. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: fix double newlines in debug outputJohan Hovold2012-04-251-3/+3
| | | | | | | Remove trailing newlines from debug messages. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: remove redundant write-urb killJohan Hovold2012-04-251-1/+0
| | | | | | | | | Since commit 1ce7b9349fad ("USB: serial: reuse generic write urb and bulk-out buffer") the port write_urb is simply a pointer to the first member of write_urbs so there's no need to kill it twice. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* usb-serial: new API for driver registrationAlan Stern2012-02-241-11/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* USB: serial: use dev_err_console in generic writeJohan Hovold2012-02-101-3/+1
| | | | | | | | Use dev_err_console in write path so that an error at least gets reported once. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: fix console error reportingJohan Hovold2012-02-101-1/+3
| | | | | | | | | | Do not report errors in write path if port is used as a console as this may trigger the same error (and error report) resulting in a loop. Reported-by: Stephen Hemminger <shemminger@vyatta.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: serial: add support for multiple read urbsJohan Hovold2011-11-151-21/+62
| | | | | | | | | | 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>
* USB: serial: handle Data Carrier Detect changesLibor Pechacek2011-01-221-0/+20
| | | | | | | | | | | | | | | | | Alan's commit 335f8514f200e63d689113d29cb7253a5c282967 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2010-08-281-6/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: pxa27x_keypad - remove input_free_device() in pxa27x_keypad_remove() Input: mousedev - fix regression of inverting axes Input: uinput - add devname alias to allow module on-demand load Input: hil_kbd - fix compile error USB: drop tty argument from usb_serial_handle_sysrq_char() Input: sysrq - drop tty argument form handle_sysrq() Input: sysrq - drop tty argument from sysrq ops handlers
| * USB: drop tty argument from usb_serial_handle_sysrq_char()Dmitry Torokhov2010-08-211-5/+3
| | | | | | | | | | | | | | | | | | | | 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>
| * Input: sysrq - drop tty argument form handle_sysrq()Dmitry Torokhov2010-08-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sysrq operations do not accept tty argument anymore so no need to pass it to us. [Stephen Rothwell <sfr@canb.auug.org.au>: fix build breakage in drm code caused by sysrq using bool but not including linux/types.h] [Sachin Sant <sachinp@in.ibm.com>: fix build breakage in s390 keyboadr driver] 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>
* | USB: serial: export symbol usb_serial_generic_disconnectBill Pemberton2010-08-231-0/+1
|/ | | | | | | | This is needed by the ssu100 driver to use this function. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: fix stalled writesJohan Hovold2010-08-101-5/+10
| | | | | | | | | | | | | | | | | | | | As David VomLehn points out, it was possible to receive an interrupt before clearing the free-urb flag which could lead to the urb being incorrectly marked as busy. For the same reason, move tx_bytes accounting so that it will never be negative. Note that the free-flags set and clear operations do not need any additional locking as they are manipulated while USB_SERIAL_WRITE_BUSY is set. Reported-by: David VomLehn <dvomlehn@cisco.com> Tested-by: David VomLehn <dvomlehn@cisco.com> Signed-off-by: Johan Hovold <jhovold@gmail.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: add special case for processing of empty read urbsJohan Hovold2010-05-201-0/+3
| | | | | | | | Return immediately from generic process_read_urb if urb is empty. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: remove multi-urb write from generic driverJohan Hovold2010-05-201-128/+22
| | | | | | | | | | | | | | | | | | | 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>
* USB: serial: reimplement generic fifo-based writesJohan Hovold2010-05-201-20/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* USB: serial: generalise write buffer preparationJohan Hovold2010-05-201-13/+34
| | | | | | | | | | | | | | | | | | | | | | | | | Generalise write buffer preparation. This allows for drivers to manipulate (e.g. add headers) to bulk out data before it is sent. This adds a new function pointer to usb_serial_driver: int (*prepare_write_buffer)(struct usb_serial_port *port, void **dest, size_t size, const void *src, size_t count); The function is generic and can be used with either kfifo-based or multi-urb writes: If *dest is NULL the implementation should allocate dest. If src is NULL the implementation should use the port write fifo. If not set, a generic implementation is used which simply uses memcpy or kfifo_out. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: re-implement multi-urb writes in generic driverJohan Hovold2010-05-201-76/+56
| | | | | | | | | | | | | | | | Use dynamic transfer buffer sizes since it is more efficient to let the host controller do the partitioning to fit endpoint size. This way we also do not use more than one urb per write request. Replace max_in_flight_urbs with multi_urb_write flag in struct usb_serial_driver to enable multi-urb writes. Use MAX_TX_URBS=40 and a max buffer size of PAGE_SIZE to prevent DoS attacks. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: allow custom multi-urb write bulk callbacksJohan Hovold2010-05-201-1/+1
| | | | | | | | | Allow drivers to implement their own multi-urb write bulk callbacks as we do for single urb writes. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: clean up generic write start busy testJohan Hovold2010-05-201-11/+4
| | | | | | | | Submit write urb if it is not already in use and we have buffered data. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: clean up some error and debug messages in generic driverJohan Hovold2010-05-201-9/+4
| | | | | | | | | Clean up error messages on usb_submit_urb failure. Remove debug message on zero-length writes. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: export generic throttle and unthrottleJohan Hovold2010-05-201-0/+2
| | | | | | | | | | | | Allow drivers to use the generic throttle and unthrottle implementation. This makes sense for drivers using the generic read functionality. Note that drivers need to set these explicitly in order to enable them (i.e., we do not set them at port probe if not defined). Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* USB: serial: generalise generic read implementationJohan Hovold2010-05-201-2/+3
| | | | | | | | | | | | | | Add process_read_urb to usb_serial_driver so that a driver can rely on the generic read (and throttle) mechanism but still do device specific processing of incoming data (such as adding tty_flags before pushing to line discipline). The default generic implementation handles sysrq for consoles but otherwise simply pushes to tty. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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