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 susp_lock after determining the
device is idle but before setting the suspended flag, thus leaving a
window where a concurrent write() can submit an urb.

Fixes: 383cedc3 ("USB: serial: full autosuspend support for the
option driver")

Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We find a race between write and resume. usb_wwan_resume run play_delayed()
and spin_unlock, but intfdata->suspended still is not set to zero.
At this time usb_wwan_write is called and anchor the urb to delay
list. Then resume keep running but the delayed urb have no chance
to be commit until next resume. If the time of next resume is far
away, tty will be blocked in tty_wait_until_sent during time. The
race also can lead to writes being reordered.

This patch put play_Delayed and intfdata->suspended together in the
spinlock, it's to avoid the write race during resume.

Fixes: 383cedc3 ("USB: serial: full autosuspend support for the
option driver")
Signed-off-by: xiao jin <jin.xiao@intel.com>
Signed-off-by: Zhang, Qi1 <qi1.zhang@intel.com>
Reviewed-by: David Cohen <david.a.cohen@linux.intel.com>
Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

When enable usb serial for modem data, sometimes the tty is blocked
in tty_wait_until_sent because portdata->out_busy always is set and
have no chance to be cleared.

We find a bug in write error path. usb_wwan_write set portdata->out_busy
firstly, then try autopm async with error. No out urb submit and no
usb_wwan_outdat_callback to this write, portdata->out_busy can't be
cleared.

This patch clear portdata->out_busy if usb_wwan_write try autopm async
with error.

Fixes: 383cedc3 ("USB: serial: full autosuspend support for the
option driver")
Signed-off-by: xiao jin <jin.xiao@intel.com>
Signed-off-by: Zhang, Qi1 <qi1.zhang@intel.com>
Reviewed-by: David Cohen <david.a.cohen@linux.intel.com>
Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We should call usb_mark_last_busy in all input paths, including the
interrupt completion handler.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The option line-control request has been using the wrong pipe direction,
while relying on USB core to fix it up.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix potential I/O while runtime suspended due to missing PM operations
in send_setup.

Fixes: 383cedc3 ("USB: serial: full autosuspend support for the
option driver")

Cc: <stable@vger.kernel.org>        # v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use tty-port initialised flag rather than private flag to determine when
port is closing down.

Since the tty-port flag is set prior to dropping DTR/RTS (when HUPCL is
set) this avoid submitting the read urbs when resuming the interface in
dtr_rts() only to immediately kill them again in shutdown().
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Move usb_autopm_get_interface_no_resume to the end of close(). This
makes the window during which suspend is prevented before the final put
in USB serial core slightly smaller.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Refactor and clean up delayed-urb submission at resume.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Clean up suspend() somewhat and make sure to always set the suspended
flag (although it's only used for runtime PM) in order to match
resume().
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use usb_get_serial_data() rather than accessing the private pointer
directly.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The tty-port implementation has already made sure that DTR/RTS have been
raised and lowered by calling dtr_rts so remove the redundant calls from
open and close.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Do not resume any I/O, including the delayed write queue, on closed
ports.

Note that this currently has no functional impact due to the
usb_autopm_get_interface() in close(), but that call is about to be
removed by a follow-up patch.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove no longer needed disconnected test from close, which is never
called post disconnect (and drivers must handle failed I/O during
disconnect anyway).
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The driver does not implement set_termios so the operation can be left
unset (tty will do the tty_termios_copy_hw for us).

Note that the send_setup call is bogus as it really only sets DTR/RTS
to their current values.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove unused variable from sierra_release_urb.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove bogus endpoint-address test which is never true.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The sierra line-control request has been using the wrong pipe direction,
while relying on USB core to fix it up.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add error message to resume error path and make sure to also return an
error when failing to submit a cached write.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure to stop all I/O, including any active write urbs, at shutdown.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix characters potentially being dropped at close due to missing
chars_in_buffer implementation.

Note that currently the write urbs are not even killed at close (will be
fixed separately), but this could still lead to dropped data since we
have lowered DTR/RTS.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure that needs_remote_wake up is always set when there are open
ports.

Currently close() would unconditionally set needs_remote_wakeup to 0
even though there might still be open ports. This could lead to blocked
input and possibly dropped data on devices that do not support remote
wakeup (and which must therefore not be runtime suspended while open).

Add an open_ports counter (protected by the susp_lock) and only clear
needs_remote_wakeup when the last port is closed.

Fixes: e6929a90 ("USB: support for autosuspend in sierra while
online")

Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The delayed-write queue was never emptied on disconnect, something which
would lead to leaked urbs and transfer buffers if the device is
disconnected before being runtime resumed due to a write.

Fixes: e6929a90 ("USB: support for autosuspend in sierra while
online")

Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Neither the transfer buffer or the urb itself were released in the
resume error path for delayed writes. Also on errors, the remainder of
the queue was not even processed, which leads to further urb and buffer
leaks.

The same error path also failed to balance the outstanding-urb counter,
something which results in degraded throughput or completely blocked
writes.

Fix this by releasing urb and buffer and balancing counters on errors,
and by always processing the whole queue even when submission of one urb
fails.

Fixes: e6929a90 ("USB: support for autosuspend in sierra while
online")

Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix use after free or NULL-pointer dereference during suspend and
resume.

The port data may never have been allocated (port probe failed)
or may already have been released by port_remove (e.g. driver is
unloaded) when suspend and resume are called.

Fixes: e6929a90 ("USB: support for autosuspend in sierra while
online")

Cc: <stable@vger.kernel.org>	# v2.6.32
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix AA deadlock in open error path that would call close() and try to
grab the already held disc_mutex.

Fixes: b9a44bc1 ("sierra: driver urb handling improvements")

Cc: <stable@vger.kernel.org>	# v2.6.31
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use a more standard logging style.

Add terminating newlines to formats.
Remove __func__ as that can be added via dynamic debug.
Remove now unnecessary debug module parameter.
Remove the dbg macro too.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use a newline character appropriately.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Matching on interface numbers was not such a good idea
for multi-function serial devices after all. It is much
better do create well defined device layouts, allowing
a single match entry per device.

Remove this now unused code.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

All the "non Gobi" Qualcomm based devices handled by this
driver share a common standard Sierra Wireless specific
layout. Adding code specifically for this layout allow
us to reduce the number of match entries per device from
three to one.

This change will result in a penalty wrt stable backports,
but simplifies new Sierra device addtitions in the long
term.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Preparing for more supported standard device layouts. Keeping
the matching macros unchanged to avoid breaking stable
backporting of new device additions.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Use a consistent style for all multiline comments.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add better error messages during the channel change/reservation establish
process.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make the transition to the UWB_RSV_STATE_NONE state synchronous so that
there is not a race between uwb_rsv_terminate and uwb_rsv_establish.
uwb_rsv_terminate would set the rsv->state to UWB_RSV_STATE_NONE but did
not release the stream resource until a 320ms timeout had expired.  If a
user called uwb_rsv_establish during that time, it could fail to
establish the reservation because no stream resources were available.
This patch removes the timer from the uwb_rsv_terminate process since it
is not needed when transitioning to UWB_RSV_STATE_NONE.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using devm_ioremap_resource() API should actually be preferred over
devm_ioremap(), since the former request the mem region first and then
gives back the ioremap'ed memory pointer.
devm_ioremap_resource() calls request_mem_region(), therby preventing
other drivers to make any overlapping call to the same region.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using devm_ioremap_resource() API should actually be preferred over
devm_ioremap(), since the former request the mem region first and then
gives back the ioremap'ed memory pointer.
devm_ioremap_resource() calls request_mem_region(), therby preventing
other drivers to make any overlapping call to the same region.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using devm_ioremap_resource() API should actually be preferred over
devm_ioremap(), since the former request the mem region first and then
gives back the ioremap'ed memory pointer.
devm_ioremap_resource() calls request_mem_region(), therby preventing
other drivers to make any overlapping call to the same region.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using devm_ioremap_resource() API should actually be preferred over
devm_ioremap(), since the former request the mem region first and then
gives back the ioremap'ed memory pointer.
devm_ioremap_resource() calls request_mem_region(), therby preventing
other drivers to make any overlapping call to the same region.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using devm_ioremap_resource() API should actually be preferred over
devm_ioremap(), since the former request the mem region first and then
gives back the ioremap'ed memory pointer.
devm_ioremap_resource() calls request_mem_region(), therby preventing
other drivers to make any overlapping call to the same region.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Using devm_ioremap_resource() API should actually be preferred over
devm_ioremap(), since the former request the mem region first and then
gives back the ioremap'ed memory pointer.
devm_ioremap_resource() calls request_mem_region(), therby preventing
other drivers to make any overlapping call to the same region.
Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>