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path: root/drivers/misc/mei/bus.c
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2018-03-14mei: make module referencing local to the bus.cTomas Winkler1-32/+34
Module reference counting is relevant only to the mei client devices. Make the implementation clean and move it to bus.c Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-16mei: set device client to the disconnected state upon suspend.Tomas Winkler1-6/+0
This fixes regression introduced by commit 8d52af6795c0 ("mei: speed up the power down flow") In mei_cldev_disable during device power down flow, such as suspend or system power off, it jumps over disconnecting function to speed up the power down process, however, because the client is unlinked from the file_list (mei_cl_unlink) mei_cl_set_disconnected is not called from mei_cl_all_disconnect leaving resource leaking. The most visible is reference counter on underlying HW module is not decreased preventing to remove modules after suspend/resume cycles. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Fixes: 8d52af6795c0 ("mei: speed up the power down flow") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19mei: fix spelling mistake: "botther" -> "bother"Colin Ian King1-1/+1
Trivial fix to spelling mistake in dev_dbg debug message. Also add in a missing comma. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-13mei: speed up the power down flowTomas Winkler1-2/+8
When mei driver is powering down due to suspend or shutdown it will iterate over the mei client bus and disconnect each client device attached in turn. The power down flow consist of the link rest, which causes all clients get disconnected at once, hence the individual disconnection can be omitted and significantly reduce power down flow. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28mei: make device_type constBhumika Goyal1-1/+1
Make this const as it is only stored in the type field of a device structure, which is const. Done using Coccinelle. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-12Merge 4.12-rc5 into char-misc-nextGreg Kroah-Hartman1-1/+3
We want the char/misc driver fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03mei: make sysfs modalias format similar as uevent modaliasPratyush Anand1-1/+3
modprobe is not able to resolve sysfs modalias for mei devices. # cat /sys/class/watchdog/watchdog0/device/watchdog/watchdog0/device/modalias mei::05b79a6f-4628-4d7f-899d-a91514cb32ab: # modprobe --set-version 4.9.6-200.fc25.x86_64 -R mei::05b79a6f-4628-4d7f-899d-a91514cb32ab: modprobe: FATAL: Module mei::05b79a6f-4628-4d7f-899d-a91514cb32ab: not found in directory /lib/modules/4.9.6-200.fc25.x86_64 # cat /lib/modules/4.9.6-200.fc25.x86_64/modules.alias | grep 05b79a6f-4628-4d7f-899d-a91514cb32ab alias mei:*:05b79a6f-4628-4d7f-899d-a91514cb32ab:*:* mei_wdt commit b26864cad1c9 ("mei: bus: add client protocol version to the device alias"), however sysfs modalias is still in formmat mei:S:uuid:*. This patch equates format of uevent and sysfs modalias so that modprobe is able to resolve the aliases. Cc: <stable@vger.kernel.org> 4.7+ Fixes: commit b26864cad1c9 ("mei: bus: add client protocol version to the device alias") Signed-off-by: Pratyush Anand <panand@redhat.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25mei: make mei_cl_bus_rescan staticAlexander Usyskin1-1/+1
mei_cl_bus_rescan is used only in bus.c, so make it local to the file and mark static. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08mei: drop amthif internal clientAlexander Usyskin1-6/+0
AMTHIF has special support in the mei drive, it handles multiplexing multiple user space connection above single me client connection. Since there is no additional addressing information there is a strict requirement on the traffic order on each connection and on the "read after write" order within the connection. This creates a lot of complexity mostly because the other client types do not necessarily fall under the same restriction. After carefully studying the use of the AMTHIF client, we came to conclusion that the multiplexing is not really utilized by any application and we may safely remove that support and significantly simplify the driver. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from ↵Ingo Molnar1-1/+1
<linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-31mei: bus: unregister callbacks upon me client disable callAlexander Usyskin1-8/+22
Stop and unregister receive and notification callbacks from the disable function, to allow its later re-enablement. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-31mei: bus: prevent hardware module unload if device on bus is activeAlexander Usyskin1-0/+31
The hardware module should not be unloaded if the bus has active devices. Get get_/put_ bus parent module upon client device connection/disconnection, to prevent the hardware managing module to disappear underneath. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-31mei: bus: cancel and disable callback after release callAlexander Usyskin1-4/+4
A driver on the mei bus may rely on the availability of the receive callback during driver remove() call, e.g. mei_wdt. Move callbacks dismantling after the remove() call to unblock that scenario. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-04mei: bus: fix mei_cldev_enable KDocAlexander Usyskin1-1/+1
Adjust function name in KDoc. Fixes: d49dc5e76fc9 (mei: bus: use mei_cldev_ prefix for the API functions) Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-06mei: bus: enable non-blocking RXAlexander Usyskin1-2/+29
Enable non-blocking receive for drivers on mei bus, this allows checking for data availability by mei client drivers. This is most effective for fixed address clients, that lacks flow control. This function adds new API function mei_cldev_recv_nonblock(), it retuns -EGAIN if function will block. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-17mei: bus: split RX and async notification callbacksAlexander Usyskin1-59/+82
Split callbacks for RX and async notification events on mei bus to eliminate synchronization problems and to open way for RX optimizations. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-17mei: bus: make a client pointer always availableAlexander Usyskin1-16/+15
Change life time of the client pointer, allocate it upon client device creation and free it upon device destruction, instead of upon connection and disconnection. This helps to eliminate racy NULL checks in the bus code. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-10mei: enable to set the internal flag for client writeAlexander Usyskin1-4/+6
Prepare the client write functions to set the internal flag in message header. Carry both blocking and internal modes inside the transmit cb, and call internal bus function __mei_cl_send() with send mode bit mask. The Internal flag should be added only on messages generated by the driver. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31mei: bus: demote error to debug level upon disconnectAlexander Usyskin1-1/+1
A mei client driver on the mei client bus can call disconnect function on already internal disconnected client. A client can disconnect internally, for example, during link reset or upon FW request. Those are legitimate flows and we should not log an error message, hence we demote 'Already disconnected' message to the debug level. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28mei: bus: remove rx callback contextTomas Winkler1-4/+2
The callback context is redunant as all the information can be retrived from the device struture of its private data. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30mei: amthif: fix deadlock in initialization during a resetAlexander Usyskin1-2/+0
The device lock was unnecessary obtained in bus rescan work before the amthif client search. That causes incorrect lock ordering and task hang: ... [88004.613213] INFO: task kworker/1:14:21832 blocked for more than 120 seconds. ... [88004.645934] Workqueue: events mei_cl_bus_rescan_work ... The correct lock order is cl_bus_lock device_lock me_clients_rwsem Move device_lock into amthif init function that called after me_clients_rwsem is released. This fixes regression introduced by commit: commit 025fb792bac3 ("mei: split amthif client init from end of clients enumeration") Cc: <stable@vger.kernel.org> # 4.6+ Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30mei: add wrapper for queuing control commands.Tomas Winkler1-2/+2
Enclose the boiler plate code of allocating a control/hbm command cb and enqueueing it onto ctrl_wr.list in a convenient wrapper mei_cl_enqueue_ctrl_wr_cb(). This is a preparatory patch for enabling consecutive reads. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30mei: fix return value on disconnectionTomas Winkler1-1/+1
Correct errno on client disconnection is -ENODEV not -EBUSY Cc: <stable@vger.kernel.org> #4.3+ Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30mei: drop read complete queue emptiness checkAlexander Usyskin1-1/+2
In the course of the read flow we want to wait for read completion only if the read queue is empty. However the calling list_empty(&cl->rd_completed) is a duplication as the same check was performed by mei_cl_read_cb() and the waiting is skipped if it returns not NULL. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04mei: bus: call mei_cl_read_start under device lockAlexander Usyskin1-3/+12
Ensure that mei_cl_read_start is called under the device lock also in the bus layer. The function updates global ctrl_wr_list which should be locked. Cc: <stable@vger.kernel.org> #4.4+ Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01mei: do not pin module if cldrv->probe() failedAlexey Khoroshilov1-2/+6
If cldrv->probe() failed in mei_cl_device_probe(), the mei module is left pinned. The patch moves __module_get(THIS_MODULE) after cldrv->probe(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-01mei: bus: use scnprintf in *_showRasmus Villemoes1-15/+4
There's no reason to duplicate the logic provided by scnprintf(). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-12mei: fix double freeing of a cb during link resetAlexander Usyskin1-3/+1
Fix double freeing of the cb that can happen if link reset kicks in the middle of blocked write from a device on the cl bus. Free cb inside mei_cl_write function on failure and drop cb free operation from callers, during a link reset the mei_cl_write function returns with an error, but the caller doesn't know if the cb was already queued or not so it doesn't know if the cb will be freed upon queue reclaim or it has to free it itself. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-08mei: split amthif client init from end of clients enumerationAlexander Usyskin1-0/+8
The amthif FW client can appear after the end of client enumeration. Amthif host client initialization is done now at FW client discovery time. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-08mei: bus: run rescan on me_clients list changeAlexander Usyskin1-0/+8
Since clients can be now added and removed during runtime we need to run bus rescan whenever me_clients list is modified. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-08mei: drop reserved host client idsAlexander Usyskin1-1/+1
The reserved host clients can be obsoleted now, a portion of the platforms is shipped without iAMT enabled, where the reservation is not relevant and for platforms with iAMT dynamic allocation is sufficient. Dropping reserved ids makes enumeration more flexible and generic Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-08mei: bus: check if the device is enabled before data transferAlexander Usyskin1-0/+9
The bus data transfer interface was missing the check if the device is in enabled state, this may lead to stack corruption during link reset. Cc: <stable@vger.kernel.org> #4.0 Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-08mei: bus: fix notification event deliveryTomas Winkler1-4/+9
Call wake_up cl->ev_wait only in case there is no bus client registered to the event notification. Second, since we don't have exclusive waiter wake_up_interruptible_all is not used correctly here. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-08mei: bus: fix RX event schedulingTomas Winkler1-4/+9
In this particular case this more correct and safer to check if the RX event is set in the event mask rather than query waitqueue_active Since the check is already performed in the mei_cl_bus_rx_event function, it is just required to check for its return value. Second, since we don't have exclusive waiter wake_up_interruptible_all is not used correctly here. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-29mei: bus: set the device name before running fixupTomas Winkler1-4/+16
The mei bus fixup use dev_xxx services for printing to kernel log so we need to setup the device name prior to running fixup hooks. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-29mei: bus: use correct lock orderingTomas Winkler1-5/+13
The correct lock order is cl_bus_lock device_lock me_clients_rwsem This order was violated in bus rescan and remove routines when me_client_rwsem was locked before cl_bus_lock. Chain exists of: [ 4.321653] &dev->device_lock --> &dev->me_clients_rwsem --> &dev->cl_bus_lock [ 4.321653] [ 4.321679] Possible unsafe locking scenario: [ 4.321679] [ 4.321693] CPU0 CPU1 [ 4.321701] ---- ---- [ 4.321709] lock(&dev->cl_bus_lock); [ 4.321720] lock(&dev->me_clients_rwsem); [ 4.321733] lock(&dev->cl_bus_lock); [ 4.321745] lock(&dev->device_lock); [ 4.321755] [ 4.321755] *** DEADLOCK *** [ 4.321755] Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-18mei: bus: fix c&p issue in the kdocTomas Winkler1-2/+2
s/send/receive/ The buffer in the receive function is not used for sending Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21mei: bus: use mei_cl_bus_ prefix consistentlyTomas Winkler1-13/+14
Use mei_cl_bus_ for internal bus function consistently. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21mei: bus: use mei_cldev_ prefix for the API functionsTomas Winkler1-33/+34
Use mei_cldev_ prefix for all mei client bus api functions in order to resolve prefix conflict with functions that handle client function and are defined in client.c Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21mei: bus: export mei_cldev_enabled functionTomas Winkler1-0/+13
Let me client device driver query of the device is connected and hence enabled. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21mei: bus: export uuid and protocol version to mei_cl bus driversTomas Winkler1-0/+26
Export the uuid and the protocol version of the underlying me client for me client bus drivers usage. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21mei: bus: add client protocol version to the device aliasTomas Winkler1-7/+21
The device alias now looks like mei:S:uuid:N:* In that way we can bind different drivers to clients with different protocol versions if required. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21mei: bus: export client protocol versionTomas Winkler1-0/+18
export me client protocol version to sysfs and uevent Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21mei: make modules.alias UUID information easier to readPrarit Bhargava1-5/+2
scripts/mod/file2alias.c:add_uuid() convert UUID into a single string which does not conform to the standard little endian UUID formatting. This patch changes add_uuid() to output same format as %pUL and modifies the mei driver to match the change. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04mei: bus: add and call callback on notify eventAlexander Usyskin1-4/+46
Enable drivers on mei client bus to subscribe to asynchronous event notifications. Introduce events_mask to the existing callback infrastructure so it is possible to handle both RX and event notification. Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04mei: bus: link client devices instead of host clientsTomas Winkler1-66/+147
MEI bus was designed around nfc and was hard to extend. Instead of the hard coded way of adding the devices on the mei bus we scan the whole me client list and create a device for each eligible me client (mei_cl_bus_rescan); currently we support only clients with single connection and fixed address clients. NFC radio name detection is run as a fixup routine The patch replaces handling the device list based on struct me_cl to device list based on me_cl_devices. The creating a connection is pushed from the device creation time to device enablement. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04mei: bus: simplify how we build nfc bus nameTomas Winkler1-1/+1
Remove the dependency on struct ndev from the nfc device name creation function so it is possible to use it in a fixup routine Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04mei: bus: enable running fixup routines before device registrationTomas Winkler1-15/+76
Split the device registration into allocation and device struct initialization, device setup, and the final device registration. This why it is possible to run fixups and quirks during the setup stage on an initialized device. Each fixup routine effects do_match flag. If the flag is set to false at the end the device won't be registered on the bus. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04mei: bus: add me client device list infrastructureTomas Winkler1-0/+1
Instead of holding the list of host clients (me_cl) we want to keep the list me client devices (mei_cl_device) This way we can create host to me client connection only when needed. Add list head to mei_cl_device and cl_bus_lock Add bus_added flag to the me client (mei_me_client) to track if the appropriate mei_cl_device was already created and is_added flag to mei_cl_device to track if it was already added to the device list across the bus rescans Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04mei: bus: add reference to bus device in struct mei_cl_clientTomas Winkler1-0/+17
Add reference to the bus device (mei_device) for easier access. To ensures that referencing cldev->bus is valid during cldev life time we increase the bus ref counter on a client device creation and drop it on the device release. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>