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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
