Fixing: net/nfc/nci/ntf.c:106:31: warning: cast to restricted __le16
message when building with make C=1 CF=-D__CHECK_ENDIAN__
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Fix warnings:
net/nfc/llcp_commands.c:421:14: warning: incorrect type in assignment (different base types)
net/nfc/llcp_commands.c:421:14: expected unsigned short [unsigned] [usertype] miux
net/nfc/llcp_commands.c:421:14: got restricted __be16
net/nfc/llcp_commands.c:477:14: warning: incorrect type in assignment (different base types)
net/nfc/llcp_commands.c:477:14: expected unsigned short [unsigned] [usertype] miux
net/nfc/llcp_commands.c:477:14: got restricted __be16
Procedure to reproduce:
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Some pipe are only created by other host (different than the
Terminal Host).
The pipe values will for example be notified by
NFC_HCI_ADM_NOTIFY_PIPE_CREATED.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
se_io allows to send apdu over the CLF to the embedded
Secure Element.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Some tag might get deactivated after some read or write tentative.
This may happen for example with Mifare Ultralight C tag when trying
to read the last 4 blocks (starting block 0x2c) configured as write
only.
NFC_CMD_ACTIVATE_TARGET will try to reselect the tag in order to
detect if it got remove from the field or if it is still present.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
nci_rf_deactivate_req only support NCI_DEACTIVATE_TYPE_IDLE_MODE.
In some situation, it might be necessary to be able to support other
NCI_DEACTIVATE_TYPE such as NCI_DEACTIVATE_TYPE_SLEEP_MODE in order for
example to reactivate the selected target.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
A notification for rf deaction can be IDLE_MODE, SLEEP_MODE,
SLEEP_AF_MODE and DISCOVERY. According to each type and the NCI
state machine is different (see figure 10 RF Communication State
Machine in NCI specification)
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The nci status byte was ignored. In case of tag reading for example,
if the tag is removed from the antenna there is no way for the upper
layers (aka: stack) to get inform about such event.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When switching from UICC to another, the CLF may signals to the Terminal
Host that some existing pipe are cleared for future update.
This notification needs to be "acked" by the Terminal Host with a ANY_OK
message.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
If our terminal connect with other host like UICC, it may create
a pipe with us, the host controller will notify us new pipe
created, after that UICC will open that pipe, if we don't handle
that request, UICC may failed to continue initialize which may
lead to card emulation feature failed to work
Signed-off-by: Arron Wang <arron.wang@intel.com>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
se_io allows to send apdu over the CLF to the embedded Secure Element.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Some NFC controller using NCI protocols may need a proprietary commands
flow to disable a secure element
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Some NFC controller using NCI protocols may need a proprietary commands
flow to enable a secure element
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Some NFC controller using NCI protocols may need a proprietary commands
flow to discover all available secure element
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Fix sparse warning introduced by commit: 9e87f9a9c4
It was generating the following warning:
net/nfc/nci/ntf.c:170:7: sparse: symbol 'nci_get_prop_rf_protocol' was not declared. Should it be static?
Procedure to reproduce it:
# apt-get install sparse
git checkout 9e87f9a9c4
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
se_io allows to send apdu over the CLF to the embedded Secure Element.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Before signaling the deactivation, send a deactivation request if in
RFST_DISCOVERY state because neard assumes polling is stopped and will
try to restart it.
Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When the deactivation type reported by RF_DEACTIVATE_NTF is Discovery, go in
RFST_DISCOVERY state. The NFCC stays in Poll mode and/or Listen mode.
Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
As specified in NCI 1.0 and NCI 1.1, when using the NFC-DEP RF Interface, the
DH and the NFCC shall only use the Static RF Connection for data communication
with a Remote NFC Endpoint.
Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The Target responds to the ATR_REQ with the ATR_RES. Configure the General
Bytes in ATR_RES with the first three octets equal to the NFC Forum LLCP
magic number, followed by some LLC Parameters TLVs described in section
4.5 of [LLCP].
Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Changes:
* Extract the Listen mode activation parameters from RF_INTF_ACTIVATED_NTF.
* Store the General Bytes of ATR_REQ.
* Signal that Target mode is activated in case of an activation in NFC-DEP.
* Update the NCI state accordingly.
* Use the various constants defined in nfc.h.
* Fix the ATR_REQ and ATR_RES maximum size. As per NCI 1.0 and NCI 1.1, the
Activation Parameters for both Poll and Listen mode contain all the bytes of
ATR_REQ/ATR_RES starting and including Byte 3 as defined in [DIGITAL].
In [DIGITAL], the maximum size of ATR_REQ/ATR_RES is 64 bytes and they are
numbered starting from Byte 1.
Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Send LA_SEL_INFO and LF_PROTOCOL_TYPE with NFC-DEP protocol enabled.
Configure 212 Kbit/s and 412 Kbit/s bit rates for Listen F.
Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The Target mode protocols are given to the nci_start_poll() function
but were previously ignored.
To enable P2P Target, when NFC-DEP is requested as a Target mode protocol, add
NFC-A and NFC-F Passive Listen modes in RF_DISCOVER_CMD command.
Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
list_for_each_entry_safe() is necessary if list objects are deleted from
the list while traversing it. Not the case here, so we can use the base
list_for_each_entry variant.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When an NFC-DEP target receives an ATN PDU, its
supposed to respond with a similar ATN PDU.
When the Target receives an I PDU with the PNI
one less than the current PNI and the last PDU
sent was an ATN PDU, the Target is to resend the
last non-ATN PDU that it has sent. This is
described in section 14.12.3.4 of the NFC Digital
Protocol Spec.
The digital layer's NFC-DEP code doesn't implement
this so add that support.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When an NFC-DEP Initiator times out when waiting for
a DEP_RES from the Target, its supposed to send an
ATN to the Target. The Target should respond to the
ATN with a similar ATN PDU and the Initiator can then
resend the last non-ATN PDU that it sent. No more
than 'N(retry,atn)' are to be send where
2 <= 'N(retry,atn)' <= 5. If the Initiator had just
sent a NACK PDU when the timeout occurred, it is to
continue sending NACKs until 'N(retry,nack)' NACKs
have been send. This is described in section
14.12.5.6 of the NFC-DEP Digital Protocol Spec.
The digital layer's NFC-DEP code doesn't implement
this so add that support.
The value chosen for 'N(retry,atn)' is 2.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When an NFC-DEP Target receives a NACK PDU with
a PNI equal to 1 less than the current PNI, it
is supposed to re-send the last PDU. This is
implied in section 14.12.5.4 of the NFC Digital
Protocol Spec.
The digital layer's NFC-DEP code doesn't implement
Target-side NACK handing so add it. The last PDU
that was sent is saved in the 'nfc_digital_dev'
structure's 'saved_skb' member. The skb will have
an additional reference taken to ensure that the skb
isn't freed when the driver performs a kfree_skb()
on the skb. The length of the skb/PDU is also saved
so the length can be restored when re-sending the PDU
in the skb (the driver will perform an skb_pull() so
an skb_push() needs to be done to restore the skb's
data pointer/length).
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When an NFC-DEP Initiator receives a frame with
an incorrect CRC or with a parity error, and the
frame is at least 4 bytes long, its supposed to
send a NACK to the Target. The Initiator can
send up to 'N(retry,nack)' consecutive NACKs
where 2 <= 'N(retry,nack)' <= 5. When the limit
is exceeded, a PROTOCOL EXCEPTION is raised.
Any other type of transmission error is to be
ignored and the Initiator should continue
waiting for a new frame. This is described
in section 14.12.5.4 of the NFC Digital Protocol
Spec.
The digital layer's NFC-DEP code doesn't implement
any of this so add it. This support diverges from
the spec in two significant ways:
a) NACKs will be sent for ANY error reported by the
driver except a timeout. This is done because
there is currently no way for the digital layer
to distinguish a CRC or parity error from any
other type of error reported by the driver.
b) All other errors will cause a PROTOCOL EXCEPTION
even frames with CRC errors that are less than 4
bytes.
The value chosen for 'N(retry,nack)' is 2.
Targets do not send NACK PDUs.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When the peer in an NFC-DEP exchange has a
packet to send that is larger than the local
maximum payload, it sets the 'MI' bit in the
'I' PDU. This indicates that NFC-DEP chaining
is to occur.
When such a PDU is received, the local side
responds with an 'ACK' PDU and this continues
until the peer sends an 'I' PDU with the 'MI'
bit cleared. This indicates that the chaining
sequence is complete and the entire packet has
been transferred.
Receiving chained PDUs is currently not supported
by the digital layer so add that support. When a
chaining sequence is initiated by the peer, the
digital layer will allocate an skb large enough
to hold 8 maximum sized frame payloads. The maximum
payload can range from 64 to 254 bytes so 8 * 254 =
2032 seems like a reasonable compromise between
potentially wasting memory and constantly reallocating
new, larger skbs.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When the NFC-DEP code is given a packet to send
that is larger than the peer's maximum payload,
its supposed to set the 'MI' bit in the 'I' PDU's
Protocol Frame Byte (PFB). Setting this bit
indicates that NFC-DEP chaining is to occur.
When NFC-DEP chaining is progress, sender 'I' PDUs
are acknowledged with 'ACK' PDUs until the last 'I'
PDU in the chain (which has the 'MI' bit cleared)
is responded to with a normal 'I' PDU. This can
occur while in Initiator mode or in Target mode.
Sender NFC-DEP chaining is currently not implemented
in the digital layer so add that support. Unfortunately,
since sending a frame may require writing the CRC to the
end of the data, the relevant data part of the original
skb must be copied for each intermediate frame.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
The maximum payload for NFC-DEP exchanges (i.e., the
number of bytes between SoD and EoD) is negotiated
using the ATR_REQ, ATR_RES, and PSL_REQ commands.
The valid maximum lengths are 64, 128, 192, and 254
bytes.
Currently, NFC-DEP code assumes that both sides are
always using 254 byte maximums and ignores attempts
by the peer to change it. Instead, implement the
negotiation code, enforce the local maximum when
receiving data from the peer, and don't send payloads
that exceed the remote's maximum. The default local
maximum is 254 bytes.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
NFC-DEP DEP_REQ and DEP_RES exchanges using 'I'
and 'ACK/NACK' PDUs have a sequence number called
the Packet Number Information (PNI). The PNI
is incremented (modulo 4) after every DEP_REQ/
DEP_RES pair and should be verified by the digital
layer code. That verification isn't always done,
though, so add code to make sure that it is done.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
According to chapter 14 of the NFC-DEP Digital
Protocol Spec., the NAD byte should never be
present in DEP_REQ or DEP_RES frames. However,
this is not enforced so add that enforcement code.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When in Target mode, the Initiator specifies whether
subsequent DEP_REQ and DEP_RES frames will include
a DID byte by the value passed in the ATR_REQ. If
the DID value in the ATR_REQ is '0' then no DID
byte will be included. If the DID value is between
'1' and '14' then a DID byte containing the same
value must be included in subsequent DEP_REQ and
DEP_RES frames. Any other DID value is invalid.
This is specified in sections 14.8.1.2 and 14.8.2.2
of the NFC Digital Protocol Spec.
Checking the DID value (if it should be there at all),
is not currently supported by the digital layer's
NFC-DEP code. Add this support by remembering the
DID value in the ATR_REQ, checking the DID value of
received DEP_REQ frames (if it should be there at all),
and including the remembered DID value in DEP_RES
frames when appropriate.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When in Initiator mode, the digital layer's
NFC-DEP code always sets the Device ID (DID)
value in the ATR_REQ to '0'. This means that
subsequent DEP_REQ and DEP_RES frames must
never include a DID byte. This is specified
in sections 14.8.1.1 and 14.8.2.1 of the NFC
Digital Protocol Spec.
Currently, the digital layer's NFC-DEP code
doesn't enforce this rule so add code to ensure
that there is no DID byte in DEP_RES frames.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Rearrange some of the code in digital_in_recv_dep_res()
and digital_tg_recv_dep_req() so the initial code looks
similar. The real reason is prepare the code for some
upcoming patches that require these changes.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
When digital_in_send_cmd() or digital_tg_send_cmd()
fail, they do not free the skb that was passed to
them so the routine that allocated the skb should
free it. Currently, there are several routines in
the NFC-DEP code that don't do this so make them.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In NFC Forum NCI specification, some RF Protocol values are
reserved for proprietary use (from 0x80 to 0xfe).
Some CLF vendor may need to use one value within this range
for specific technology.
Furthermore, some CLF may not becompliant with NFC Froum NCI
specification 2.0 and therefore will not support RF Protocol
value 0x06 for PROTOCOL_T5T as mention in a draft specification
and in a recent push.
Adding get_rf_protocol handle to the nci_ops structure will
help to set the correct technology to target.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
NCI RF FRAME interface is used for all kind of tags
except ISODEP ones. So for all other kind of tags the
status byte has to be removed.
Signed-off-by: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
All contexts have to be initiliazed before calling
nfc_register_device otherwise it is possible to call
nci_dev_up before ending the nci_register_device
function. In such case kernel will crash on non
initialized variables.
Signed-off-by: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In order to operate at the fasted bit rate
possible, add initiator-side support for
PSL REQ while in P2P mode. The PSL REQ
will switch the RF technology to 424F
whenever possible.
Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Conflicts:
net/6lowpan/iphc.c
Minor conflicts in iphc.c were changes overlapping with some
style cleanups.
John W. Linville says:
====================
Please pull this last(?) batch of wireless change intended for the
3.17 stream...
For the NFC bits, Samuel says:
"This is a rather quiet one, we have:
- A new driver from ST Microelectronics for their NCI ST21NFCB,
including device tree support.
- p2p support for the ST21NFCA driver
- A few fixes an enhancements for the NFC digital laye"
For the Atheros bits, Kalle says:
"Michal and Janusz did some important RX aggregation fixes, basically we
were missing RX reordering altogether. The 10.1 firmware doesn't support
Ad-Hoc mode and Michal fixed ath10k so that it doesn't advertise Ad-Hoc
support with that firmware. Also he implemented a workaround for a KVM
issue."
For the Bluetooth bits, Gustavo and Johan say:
"To quote Gustavo from his previous request:
'Some last minute fixes for -next. We have a fix for a use after free in
RFCOMM, another fix to an issue with ADV_DIRECT_IND and one for ADV_IND with
auto-connection handling. Last, we added support for reading the codec and
MWS setting for controllers that support these features.'
Additionally there are fixes to LE scanning, an update to conform to the 4.1
core specification as well as fixes for tracking the page scan state. All
of these fixes are important for 3.17."
And,
"We've got:
- 6lowpan fixes/cleanups
- A couple crash fixes, one for the Marvell HCI driver and another in LE SMP.
- Fix for an incorrect connected state check
- Fix for the bondable requirement during pairing (an issue which had
crept in because of using "pairable" when in fact the actual meaning
was "bondable" (these have different meanings in Bluetooth)"
Along with those are some late-breaking hardware support patches in
brcmfmac and b43 as well as a stray ath9k patch.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The digital layer of the NFC subsystem currently
supports a 'tg_listen_mdaa' driver hook that supports
devices that can do mode detection and automatic
anticollision. However, there are some devices that
can do mode detection but not automatic anitcollision
so add the 'tg_listen_md' hook to support those devices.
In order for the digital layer to get the RF technology
detected by the device from the driver, add the
'tg_get_rf_tech' hook. It is only valid to call this
hook immediately after a successful call to 'tg_listen_md'.
CC: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
stop_poll allows to stop CLF reader polling. Some other operations might be
necessary for some CLF to stop polling. For example in card mode.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Add T1T matching with Jewel during notification.
It was causing "the target found does not have the desired protocol"
to show up.
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Add new "NFC_DIGITAL_FRAMING_*" calls to the digital
layer so the driver can make the necessary adjustments
when performing anticollision while in target mode.
The driver must ensure that the effect of these calls
happens after the following response has been sent but
before reception of the next request begins.
Acked-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Currently, digital_target_found() has a race between
the events started by calling nfc_targets_found()
(which ultimately expect ddev->poll_tech_count to be
zero) and setting ddev->poll_tech_count to zero after
the call to nfc_targets_found(). When the race is
"lost" (i.e., ddev->poll_tech_count is found to not
be zero by the events started by nfc_targets_found()),
an error message is printed and the target is not found.
A similar race exists when digital_tg_recv_atr_req()
calls nfc_tm_activated().
Fix this by first saving the current value of
ddev->poll_tech_count and then clearing it before
calling nfc_targets_found()/nfc_tm_activated().
Clearing ddev->poll_tech_count before calling
nfc_targets_found()/nfc_tm_activated() eliminates
the race. Saving the value is required so it can be
restored when nfc_targets_found()/nfc_tm_activated()
fails and polling needs to continue.
Acked-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
