Commit Graph

372 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
69b7290e51 Merge 3.18-rc4 into usb-next.
This resolves a conflict in drivers/usb/host/Kconfig

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-10 12:10:24 +09:00
Johan Hovold
2a8cdfde92 USB: cdc-acm: add quirk for control-line state requests
Add new quirk for devices that cannot handle control-line state
requests.

Note that we currently send these requests to all devices, regardless of
whether they claim to support it, but that errors are only logged if
support is claimed.

Since commit 0943d8ead3 ("USB: cdc-acm: use tty-port dtr_rts"), which
only changed the timings for these requests slightly, this has been
reported to cause occasional firmware crashes on Simtec Electronics
Entropy Key devices after re-enumeration. Enable the quirk for this
device.

Reported-by: Nix <nix@esperi.org.uk>
Tested-by: Nix <nix@esperi.org.uk>
Cc: stable <stable@vger.kernel.org>	# v3.16
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-06 12:25:40 -08:00
Johan Hovold
4473d054ce USB: cdc-acm: only raise DTR on transitions from B0
Make sure to only raise DTR on transitions from B0 in set_termios.

Also allow set_termios to be called from open with a termios_old of
NULL. Note that DTR will not be raised prematurely in this case.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 11:25:25 -08:00
Peter Chen
b8f2854b06 usb: class: usbtmc: delete unnecessary 'out of memory' messages
The memory subsystem has already had similar message for it.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-03 15:42:04 -08:00
Oliver Neukum
61fbe96c8b cdc-acm: Drop the warning for unusual capabilities
Let's drop the warning for modems with unusual capabilities,
the associated quirk and blacklist. They made little sense.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-03 15:30:13 -08:00
Jim Paris
24cb4502c9 cdc-acm: ensure that termios get set when the port is activated
The driver wasn't properly configuring the hardware for the current
termios settings under all conditions.  Ensure that termios are
written to the device when the port is activated.

Signed-off-by: Jim Paris <jim@jtan.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-03 15:26:15 -08:00
Johan Hovold
cf84a691a6 USB: cdc-acm: add device id for GW Instek AFG-2225
Add device-id entry for GW Instek AFG-2225, which has a byte swapped
bInterfaceSubClass (0x20).

Reported-by: Karl Palsson <karlp@tweak.net.au>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-03 15:26:15 -08:00
Rickard Strandqvist
ab53eb9736 usb: class: usbtmc.c: Cleaning up uninitialized variables
There is a risk that the variable will be used without being initialized.

This was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 15:59:10 -07:00
Oliver Neukum
d846b7650d USB: usbtmc: fix DMA on stack
send_request_dev_dep_msg_in() use a buffer allocated on the stack.
Fix by kmalloc()ing the buffer.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 16:03:57 -07:00
Oliver Neukum
d1b781002b USB: cdc-acm: use BIT macro
Converting the header to BIT for readability. No functional
change.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 16:03:57 -07:00
Johan Hovold
0943d8ead3 USB: cdc-acm: use tty-port dtr_rts
Add dtr_rts tty-port operation which implements proper DTR/RTS handling
(e.g. only lower DTR/RTS during shutdown if HUPCL is set).

Note that modem-control locking still needs to be added throughout the
driver.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:10 -07:00
Johan Hovold
308fee18e0 USB: cdc-acm: remove redundant usb_mark_last_busy
There's no need to call usb_mark_last_busy after having increased the PM
counter in write(). The device will be marked busy by USB core when the
PM counter is balanced in the completion handler.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:10 -07:00
Johan Hovold
4a8ee5059a USB: cdc-acm: do not update PM busy on read errors
There's no need to update the runtime PM last_busy field on read urb
errors (e.g. when the urb is being killed on shutdown).

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:10 -07:00
Johan Hovold
b1d42efc21 USB: cdc-acm: minimise no-suspend window during shutdown
Now that acm_set_control() handles runtime PM properly, the only
remaining reason for the PM operations in shutdown is to clear the
needs_remote_wakeup flag before the final put.

Note that this also means that we now need to grab the write_lock to
prevent racing with resume.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:10 -07:00
Johan Hovold
89e54e4468 USB: cdc-acm: remove redundant disconnected test from shutdown
Remove redundant disconnect test from shutdown(), which is never called
post disconnect() where we do synchronous hangup.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
bbf0cb3e93 USB: cdc-acm: simplify runtime PM locking
We can simply the runtime PM locking as there's no need to check the
susp_count in the read path (at least not since killing the rx tasklet).

Specifically, the read urbs will never be resubmitted by the completion
handler when killed during suspend.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
5292afa657 USB: cdc-acm: fix runtime PM imbalance at shutdown
Make sure only to decrement the PM counters if they were actually
incremented.

Note that the USB PM counter, but not necessarily the driver core PM
counter, is reset when the interface is unbound.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
e4c36076c2 USB: cdc-acm: fix I/O after failed open
Make sure to kill any already submitted read urbs on read-urb submission
failures in open in order to prevent doing I/O for a closed port.

Fixes: 088c64f812 ("USB: cdc-acm: re-write read processing")
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
8727bf689a USB: cdc-acm: fix failed open not being detected
Fix errors during open not being returned to userspace. Specifically,
failed control-line manipulations or control or read urb submissions
would not be detected.

Fixes: 7fb57a019f ("USB: cdc-acm: Fix potential deadlock (lockdep
warning)")

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
703df3297f USB: cdc-acm: fix open and suspend race
We must not do the usb_autopm_put_interface() before submitting the read
urbs or we might end up doing I/O to a suspended device.

Fixes: 088c64f812 ("USB: cdc-acm: re-write read processing")
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
183a45087d USB: cdc-acm: fix potential urb leak and PM imbalance in write
Make sure to check return value of autopm get in write() in order to
avoid urb leak and PM counter imbalance on errors.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Cc: <stable@vger.kernel.org>	# v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
ed79707403 USB: cdc-acm: fix shutdown and suspend race
We should stop I/O unconditionally at suspend rather than rely on the
tty-port initialised flag (which is set prior to stopping I/O during
shutdown) in order to prevent suspend returning with URBs still active.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Cc: <stable@vger.kernel.org>	# v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
bae3f4c535 USB: cdc-acm: fix runtime PM for control messages
Fix runtime PM handling of control messages by adding the required PM
counter operations.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Cc: <stable@vger.kernel.org>	# v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
140cb81ac8 USB: cdc-acm: fix broken runtime suspend
The current ACM runtime-suspend implementation is broken in several
ways:

Firstly, it buffers only the first write request being made while
suspended -- any further writes are silently dropped.

Secondly, writes being dropped also leak write urbs, which are never
reclaimed (until the device is unbound).

Thirdly, even the single buffered write is not cleared at shutdown
(which may happen before the device is resumed), something which can
lead to another urb leak as well as a PM usage-counter leak.

Fix this by implementing a delayed-write queue using urb anchors and
making sure to discard the queue properly at shutdown.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Reported-by: Xiao Jin <jin.xiao@intel.com>
Cc: <stable@vger.kernel.org>	# v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
e144ed28be USB: cdc-acm: fix write and resume race
Fix race between write() and resume() due to improper locking that could
lead to writes being reordered.

Resume must be done atomically and susp_count be protected by the
write_lock in order to prevent racing with write(). This could otherwise
lead to writes being reordered if write() grabs the write_lock after
susp_count is decremented, but before the delayed urb is submitted.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Cc: <stable@vger.kernel.org>	# v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:09 -07:00
Johan Hovold
5a345c20c1 USB: cdc-acm: fix write and suspend race
Fix race between write() and suspend() which could lead to writes being
dropped (or I/O while suspended) if the device is runtime suspended
while a write request is being processed.

Specifically, suspend() releases the write_lock after determining the
device is idle but before incrementing the susp_count, thus leaving a
window where a concurrent write() can submit an urb.

Fixes: 11ea859d64 ("USB: additional power savings for cdc-acm devices
that support remote wakeup")

Cc: <stable@vger.kernel.org>        # v2.6.27
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27 15:04:08 -07:00
Michael Ulbricht
895d240d1d USB: cdc-acm: Remove Motorola/Telit H24 serial interfaces from ACM driver
By specifying NO_UNION_NORMAL the ACM driver does only use the first two
USB interfaces (modem data & control). The AT Port, Diagnostic and NMEA
interfaces are left to the USB serial driver.

Signed-off-by: Michael Ulbricht <michael.ulbricht@systec-electronic.com>
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16 14:03:40 -07:00
Alexey Khoroshilov
070c0b17f6 USB: cdc-acm: fix double usb_autopm_put_interface() in acm_port_activate()
If acm_submit_read_urbs() fails in acm_port_activate(), error handling
code calls usb_autopm_put_interface() while it is already called
before acm_submit_read_urbs(). The patch reorganizes error handling code
to avoid double decrement of USB interface's PM-usage counter.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16 13:56:08 -07:00
Bjørn Mork
f563926fed usb: cdc-wdm: resp_count can be 0 even if WDM_READ is set
Do not decrement resp_count if it's already 0.

We set resp_count to 0 when the device is closed.  The next open and
read will try to clear the WDM_READ flag if there was leftover data
in the read buffer. This fix is necessary to prevent resubmitting
the read URB in a tight loop because resp_count becomes negative.

The bug can easily be triggered from userspace by not reading all
data in the read buffer, and then closing and reopening the chardev.

Fixes: 8dd5cd5395 ("usb: cdc-wdm: avoid hanging on zero length reads")
Cc: <stable@vger.kernel.org> # 3.13
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-12 20:13:28 -08:00
Paul Gortmaker
803a536243 usb: delete non-required instances of include <linux/init.h>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-08 15:01:39 -08:00
Greg Kroah-Hartman
99f14bd4d1 Merge 3.13-rc5 into usb-next
This resolves the merge issue with drivers/usb/host/ohci-at91.c

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-24 10:18:03 -08:00
Bjørn Mork
8dd5cd5395 usb: cdc-wdm: avoid hanging on zero length reads
commit 73e06865ea ("USB: cdc-wdm: support back-to-back
USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications") implemented
queued response handling. This added a new requirement: The read
urb must be resubmitted every time we clear the WDM_READ flag if
the response counter indicates that the device is waiting for a
read.

Fix by factoring out the code handling the WMD_READ clearing and
possible urb submission, calling it everywhere we clear the flag.

Without this fix, the driver ends up in a state where the read urb
is inactive, but the response counter is positive after a zero
length read.  This prevents the read urb from ever being submitted
again and the driver appears to be hanging.

Fixes: 73e06865ea ("USB: cdc-wdm: support back-to-back USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications")
Cc: Greg Suarez <gsuarez@smithmicro.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: stable <stable@vger.kernel.org> # 3.13
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-20 12:06:46 -08:00
Greg Kroah-Hartman
d59abb9325 Merge branch 3.13-rc4 into usb-next 2013-12-16 08:46:03 -08:00
Bjørn Mork
4144bc861e usb: cdc-wdm: manage_power should always set needs_remote_wakeup
Cc: stable <stable@vger.kernel.org>
Reported-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-09 13:14:11 -08:00
David Cluytens
3b59d16c51 USB: cdc-acm: Added support for the Lenovo RD02-D400 USB Modem
Signed-off-by: David Cluytens <david.cluytens@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-04 16:53:03 -08:00
Oliver Neukum
8fdbeb26b5 cdc-acm: fix power management in ioctl
An ioctl that does depends on communication with a device should
prevent suspension of teh device.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-03 10:23:46 -08:00
Oliver Neukum
797ef13716 cdc-acm: add TIOCGICOUNT
Simple straightforward implementation. Just returning the statistics
gathered for TIOCMIWAIT

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-03 10:23:46 -08:00
Oliver Neukum
5a6a62bdb9 cdc-acm: add TIOCMIWAIT
This implements TIOCMIWAIT for TIOCM_DSR, TIOCM_RI and TIOCM_CD
Disconnect is handled as TIOCM_CD or an error.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-03 10:23:46 -08:00
Bjørn Mork
9983d6dc4e usb: cdc-wdm: ignore speed change notifications
The only notification supported by the Device Management class is
Response Available. But this driver is also used as a subdriver of
other CDC classes, allowing notifications like Speed Change and
Network Connection. This results in log messages which are only
confusing to an end user:

 [66255.801874] cdc_mbim 1-3:1.5: unknown notification 42 received: index 5 len 8

These drivers use cdc-wdm as a subdriver to allow access to an
embedded management protocol, and all management is expected to
use this protocol. There is therefore no need to handle any of
these optional CDC notifications. Instead we can let the cdc-wdm
driver recognize them and log a debug level message instead of an
error.

Reported-by: Rob Gardner <robmatic@gmail.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 17:02:41 -07:00
Greg Suarez
73e06865ea USB: cdc-wdm: support back-to-back USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications
Some MBIM devices send back-to-back USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications
when sending a message over multiple fragments or when there are unsolicited
messages available.

Count up the number of USB_CDC_NOTIFY_RESPONSE_AVAILABLE notifications received
and decrement the count and submit the urb for the next response each time userspace
completes a read the response.

Signed-off-by: Greg Suarez <gsuarez@smithmicro.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-29 17:02:41 -07:00
Greg Kroah-Hartman
2a6eb8ac9b USB: usbtmc: fix up attribute permissions
In auditing the usbtmc sysfs files, a bunch of them were being created
as "read only", yet they have logic to handle writing to.  So fix them
up by setting the permissions properly.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-25 15:12:03 -07:00
Greg Kroah-Hartman
bd479f2933 Merge 3.11-rc6 into usb-next
We want these USB fixes in this branch as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-18 20:33:01 -07:00
Oliver Neukum
6dd433e6cf USB: cdc-wdm: fix race between interrupt handler and tasklet
Both could want to submit the same URB. Some checks of the flag
intended to prevent that were missing.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
CC: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12 15:41:07 -07:00
Johan Hovold
c786138fcc USB: usbtmc: fix big-endian probe of Rigol devices
Fix probe of Rigol devices on big-endian machines. A quirk for these
devices was introduced by commit c2e314835 ("USB: usbtmc: Set
rigol_quirk if device is listed") but was only enabled on little-endian
machines.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12 13:52:35 -07:00
Andy Shevchenko
e6c7efdcb7 usbtmc: convert to devm_kzalloc
kfree(data) will be called implicitly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25 12:01:12 -07:00
Andy Shevchenko
bbf4976e77 usbtmc: remove redundant braces
There is a few cases where braces are not needed. This patch removes
unnecessary '& 255' pieces as well when lvalue type is u8.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25 12:01:12 -07:00
Andy Shevchenko
f4d844cb6c usbtmc: call pr_err instead of plain printk
Additionally remove useless label.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25 12:01:12 -07:00
Andy Shevchenko
92f78ddb10 usbtmc: remove trailing spaces
Recent patch series introduces few trailing spaces. This patch removes them.
No functional change.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25 12:01:12 -07:00
Felipe Balbi
d102e78f70 usb: class: cdc-acm: be careful with bInterval
bInterval must be on the range 1 - 16, if we
want to pass the maximum allowed, we should
be passing 16

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25 11:49:29 -07:00
Greg Kroah-Hartman
71c2fb03fc USB: cdc-acm: remove unneeded spin_lock_irqsave/restore on write path
When writing data we were:
	lock
	do some work
	unlock
	call function
		lock
		do some work
		unlock
		return
	return

It turns out, that "function" was only ever called in the one place, so
instead of locking/unlocking for no good reason, just inline the
function and only grab the lock once.

This has sped up the pathological case of sending 1 byte packets to a
loop-back cdc-acm device from 49600 bytes per second to 50100 bytes a
second on my workstation.  A tiny increase yes, but noticable, and now
the spinlock isn't the hottest thing on the perf graph anymore.  Yes, we
are still waiting for the hardware for the most part, but getting rid of
a spinlock_irq_save() call for every packet is still a good thing.

And we end up deleting lines of code, always a win overall.

This was found by using a Teensy 3.0 device and the test program and
firmware located at:
	http://www.pjrc.com/teensy/benchmark_usb_serial_receive.html

Reported-by: Paul Stoffregen <paul@pjrc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-17 13:37:07 -07:00