This patch adds a new mgmt command for enabling and disabling
LE advertising. The command depends on the LE setting being enabled
first and will return a "rejected" response otherwise. The patch also
adds safeguards so that there will ever only be one set_le or
set_advertising command pending per adapter.
The response handling and new_settings event sending is done in an
asynchronous request callback, meaning raw HCI access from user space to
enable advertising (e.g. hciconfig leadv) will not trigger the
new_settings event. This is intentional since trying to support mixed
raw HCI and mgmt access would mean adding extra state tracking or new
helper functions, essentially negating the benefit of using the
asynchronous request framework. The HCI_LE_ENABLED and HCI_LE_PERIPHERAL
flags however are updated correctly even with raw HCI access so this
will not completely break subsequent access over mgmt.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch adds a new mgmt setting for LE advertising and hooks up the
necessary places in the mgmt code to operate on the HCI_LE_PERIPHERAL
flag (which corresponds to this setting). This patch does not yet add
any new command for enabling the setting - that is left for a subsequent
patch.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch updates the code to use an asynchronous request for handling
the enabling and disabling of LE support. This refactoring is necessary
as a preparation for adding advertising support, since when LE is
disabled we should also disable advertising, and the cleanest way to do
this is to perform the two respective HCI commands in the same
asynchronous request.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The settings_rsp and cmd_status_rsp functions can be useful for all mgmt
command handlers when asynchronous request callbacks are used. They will
e.g. be used by subsequent patches to change set_le to use an async
request as well as a new set_advertising command. Therefore, move them
higher up in the mgmt.c file to avoid unnecessary forward declarations
or mixing this trivial change with other patches.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
We should return a "busy" error always when there is another
mgmt_set_powered operation in progress. Previously when powering on
while the auto off timer was still set the code could have let two or
more pending power on commands to be queued. This patch fixes the issue
by moving the check for duplicate commands to an earlier point in the
set_powered handler.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch cleans up the locking login in l2cap_sock_recvmsg by pairing
up each lock_sock call with a release_sock call. The function already
has a "done" label that handles releasing the socket and returning from
the function so the fix is rather simple.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The bt_sock_wait_state requires the sk lock to be held (through
lock_sock) so document it clearly in the code.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Convert 0 to false and 1 to true when assigning values to bool
variables. Inspired by commit 3db1cd5c05.
The simplified semantic patch that find this problem is as
follows (http://coccinelle.lip6.fr/):
@@
bool b;
@@
(
-b = 0
+b = false
|
-b = 1
+b = true
)
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When the dlc is closed, rfcomm_dev_state_change() tries to release the
port in the case it cannot get a reference to the tty. However this is
racy and not even needed.
Infact as Peter Hurley points out:
1. Only consider dlcs that are 'stolen' from a connected socket, ie.
reused. Allocated dlcs cannot have been closed prior to port
activate and so for these dlcs a tty reference will always be avail
in rfcomm_dev_state_change() -- except for the conditions covered by
#2b below.
2. If a tty was at some point previously created for this rfcomm, then
either
(a) the tty reference is still avail, so rfcomm_dev_state_change()
will perform a hangup. So nothing to do, or,
(b) the tty reference is no longer avail, and the tty_port will be
destroyed by the last tty_port_put() in rfcomm_tty_cleanup.
Again, no action required.
3. Prior to obtaining the dlc lock in rfcomm_dev_add(),
rfcomm_dev_state_change() will not 'see' a rfcomm_dev so nothing to
do here.
4. After releasing the dlc lock in rfcomm_dev_add(),
rfcomm_dev_state_change() will 'see' an incomplete rfcomm_dev if a
tty reference could not be obtained. Again, the best thing to do here
is nothing. Any future attempted open() will block on
rfcomm_dev_carrier_raised(). The unconnected device will exist until
released by ioctl(RFCOMMRELEASEDEV).
The patch removes the aforementioned code and uses the
tty_port_tty_hangup() helper to hangup the tty.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
For those controller that support the HCI_Set_Event_Mask_Page_2 command
we should include it in the init sequence. This patch implements sending
of the command and enables the events in it based on supported features
(currently only CSB is checked).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch adds support for reading the synchronization train parameters
for controllers that support the feature. Since the feature is
detectable through the local features page 2, which is retreived only in
stage 3 of the HCI init sequence, there is no other option than to add a
fourth stage to the init sequence.
For now the patch doesn't yet add storing of the parameters, but it is
nevertheless convenient to have around to see what kind of parameters
various controllers use by default (analyzable e.g. with the btmon user
space tool).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
In the case of blocking sockets we should not proceed with sendmsg() if
the socket has the BT_SK_SUSPEND flag set. So far the code was only
ensuring that POLLOUT doesn't get set for non-blocking sockets using
poll() but there was no code in place to ensure that blocking sockets do
the right thing when writing to them.
This patch adds a new bt_sock_wait_ready helper function to sleep in the
sendmsg call if the BT_SK_SUSPEND flag is set, and wake up as soon as it
is unset. It also updates the L2CAP and RFCOMM sendmsg callbacks to take
advantage of this new helper function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When we have an LE link we should not respond to any data on the BR/EDR
L2CAP signaling channel (0x0001) and vice-versa when we have a BR/EDR
link we should not respond to LE L2CAP (CID 0x0005) signaling commands.
This patch fixes this issue by checking for a valid link type and
ignores data if it is wrong.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When L2CAP packets return a non-zero error and the value is passed
onwards by l2cap_bredr_sig_cmd this will trigger a command reject packet
to be sent. However, the core specification (page 1416 in core 4.0) says
the following: "Command Reject packets should not be sent in response to
an identified Response packet.".
This patch ensures that a command reject packet is not sent for any
identified response packet by ignoring the error return value from the
response handler functions.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
There are several possible reason codes that can be sent in the command
reject L2CAP packet. Before this patch the code has used a hard-coded
single response code ("command not understood"). This patch adds a
helper function to map the return value of an L2CAP handler function to
the correct command reject reason.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
If we receive an L2CAP Disconnect Request for an unknown CID we should
not just silently drop it but reply with a proper Command Reject
response. This patch fixes this by ensuring that the disconnect handler
returns a proper error instead of 0 and will cause the function caller
to send the right response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The EFAULT error should only be used for memory address related errors
and ENOENT might be needed for other purposes than invalid CID errors.
This patch fixes the l2cap_config_req, l2cap_connect_create_rsp and
l2cap_create_channel_req handlers to use the unique EBADSLT error to
indicate failed lookups on a given CID.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When an L2CAP request handler returns non-zero the calling code will
send a command reject response. The l2cap_create_chan_req function will
in some cases send its own response but then still return a -EFAULT
error which would cause two responses to be sent. This patch fixes this
by making the function return 0 after sending its own response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The struct for HCI_Set_Event_Mask is never used. Instead a local 8-byte
array is used for sending this command. Therefore, remove the
unnecessary struct definition.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
We need to let the setup stage complete cleanly even when the HCI device
is rfkilled. Otherwise the HCI device will stay in an undefined state
and never get notified to user space through mgmt (even when it gets
unblocked through rfkill).
This patch makes sure that hci_dev_open() can be called in the HCI_SETUP
stage, that blocking the device doesn't abort the setup stage, and that
the device gets proper powered down as soon as the setup stage completes
in case it was blocked meanwhile.
The bug that this patch fixed can be very easily reproduced using e.g.
the rfkill command line too. By running "rfkill block all" before
inserting a Bluetooth dongle the resulting HCI device goes into a state
where it is never announced over mgmt, not even when "rfkill unblock all"
is run.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This makes it more convenient to check for rfkill (no need to check for
dev->rfkill before calling rfkill_blocked()) and also avoids potential
races if the RFKILL state needs to be checked from within the rfkill
callback.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch fixes the connection encryption key size information when
the host is playing the peripheral role. We should set conn->enc_key_
size in hci_le_ltk_request_evt, otherwise it is left uninitialized.
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
While playing the peripheral role, the host gets a LE Long Term Key
Request Event from the controller when a connection is established
with a bonded device. The host then informs the LTK which should be
used for the connection. Once the link is encrypted, the host gets
an Encryption Change Event.
Therefore we should set conn->pending_sec_level instead of conn->
sec_level in hci_le_ltk_request_evt. This way, conn->sec_level is
properly updated in hci_encrypt_change_evt.
Moreover, since we have a LTK associated to the device, we have at
least BT_SECURITY_MEDIUM security level.
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When the user channel is set and an user application has full control
over the device, do not bother trying to schedule any queues except
the raw queue.
This is an optimization since with user channel, only the raw queue
is in use.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
There is no need to use GFP_ATOMIC with skb_clone() when the code is
executed in a workqueue.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When the device has the user channel flag set, it means it is driven by
an user application. In that case do not allow any connections from
L2CAP or SCO sockets.
This is the same situation as when the device has the raw flag set and
it will then return EHOSTUNREACH.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
So far the only option to create a virtual AMP controller was by
setting a module parameter for the hci_vhci driver. This patch adds
the functionality to define inline to create either a BR/EDR or an
AMP controller.
In addition the client will be informed which HCI controller index
it got assigned. That is especially useful for automated end-to-end
testing.
To keep backwards compatibility with existing userspace, the command
for creating a controller type needs to be send right after opening
the device node. If the command is not send, it defaults back to
automatically creating a BR/EDR controller.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
To allow creating /dev/vhci device node, add the proper module alias for
this driver.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch introcuces a new HCI socket channel that allows user
applications to take control over a specific HCI device. The application
gains exclusive access to this device and forces the kernel to stay away
and not manage it. In case of the management interface it will actually
hide the device.
Such operation is useful for security testing tools that need to operate
underneath the Bluetooth stack and need full control over a device. The
advantage here is that the kernel still provides the service of hardware
abstraction and HCI level access. The use of Bluetooth drivers for
hardware access also means that sniffing tools like btmon or hcidump
are still working and the whole set of transaction can be traced with
existing tools.
With the new channel it is possible to send HCI commands, ACL and SCO
data packets and receive HCI events, ACL and SCO packets from the
device. The format follows the well established H:4 protocol.
The new HCI user channel can only be established when a device has been
through its setup routine and is currently powered down. This is
enforced to not cause any problems with current operations. In addition
only one user channel per HCI device is allowed. It is exclusive access
for one user application. Access to this channel is limited to process
with CAP_NET_RAW capability.
Using this new facility does not require any external library or special
ioctl or socket filters. Just create the socket and bind it. After that
the file descriptor is ready to speak H:4 protocol.
struct sockaddr_hci addr;
int fd;
fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
memset(&addr, 0, sizeof(addr));
addr.hci_family = AF_BLUETOOTH;
addr.hci_dev = 0;
addr.hci_channel = HCI_CHANNEL_USER;
bind(fd, (struct sockaddr *) &addr, sizeof(addr));
The example shows on how to create a user channel for hci0 device. Error
handling has been left out of the example. However with the limitations
mentioned above it is advised to handle errors. Binding of the user
cahnnel socket can fail for various reasons. Specifically if the device
is currently activated by BlueZ or if the access permissions are not
present.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This patch introduces a new user channel flag that allows to give full
control of a HCI device to a user application. The kernel will stay away
from the device and does not allow any further modifications of the
device states.
The existing raw flag is not used since it has a bit of unclear meaning
due to its legacy. Using a new flag makes the code clearer.
A device with the user channel flag set can still be enumerate using the
legacy API, but it does not longer enumerate using the new management
interface used by BlueZ 5 and beyond. This is intentional to not confuse
users of modern systems.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The various legacy ioctls used with HCI sockets are limited to raw
channel only. They are not used on the other channels and also have
no meaning there. So return an error if tried to use them.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The HCI sockets for monitor and control do not support any HCI specific
socket options and if tried, an error will be returned. However the
error used is EINVAL and that is not really descriptive. To make it
clear that these sockets are not handling HCI socket options, return
EBADFD instead.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Even if this is legacy API, there is no reason to not report a proper
error when trying to reset a HCI device that is down.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The hci_dev check is not protected and so move it into the socket lock. In
addition return the HCI channel identifier instead of always 0 channel.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The HCI sockets do not have a peer associated with it and so make sure
that getpeername() returns EOPNOTSUPP since this operation is actually
not supported on HCI sockets.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
The handling of the raw socket filter is rather obscure code and it gets
in the way of future extensions. Instead of inline filtering in the raw
socket packet routine, refactor it into its own function.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
My commit
commit c630ccf1a1
Author: Stanislaw Gruszka <stf_xl@wp.pl>
Date: Sat Mar 16 19:19:46 2013 +0100
rt2800: rearrange bbp/rfcsr initialization
make Maxim machine freeze when try to start wireless device.
Initialization order and sending MCU_BOOT_SIGNAL request, changed in
above commit, is important. Doing things incorrectly make PCIe bus
problems, which can froze the machine.
This patch change initialization sequence like vendor driver do:
function NICInitializeAsic() from
2011_1007_RT5390_RT5392_Linux_STA_V2.5.0.3_DPO (PCI devices) and
DPO_RT5572_LinuxSTA_2.6.1.3_20121022 (according Mediatek, latest driver
for RT8070/RT3070/RT3370/RT3572/RT5370/RT5372/RT5572 USB devices).
It fixes freezes on Maxim system.
Resolve:
https://bugzilla.redhat.com/show_bug.cgi?id=1000679
Reported-and-tested-by: Maxim Polyakov <polyakov@dexmalabs.com>
Bisected-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
On most 64 Bit systems unsigned long is 64 bit long and then -MAX_ERRNO
is out of the range of a u32 used to store the error code in.
This patch casts the -MAX_ERRNO to a u32 instead.
This fixes a regression introduced in:
commit fd4edf1975
Author: Hauke Mehrtens <hauke@hauke-m.de>
Date: Mon Jul 15 13:15:08 2013 +0200
bcma: fix handling of big addrl
Reported-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Tested-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
In case of __dev_alloc_skb() failure rtl8187_init_urbs()
calls usb_free_urb(entry) where 'entry' can points to urb
allocated at the previous iteration. That means refcnt will be
decremented incorrectly and the urb can be used after memory
deallocation.
The patch fixes the issue and implements error handling of init_urbs
in rtl8187_start().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The kernel configuration for the driver could result in
compilation issues as reported by Randy Dunlap. His results
are show below:
"on x86_64:
when
CONFIG_MMC=m
CONFIG_BRCMUTIL=y
CONFIG_BRCMFMAC=y
CONFIG_BRCMFMAC_SDIO=y
This bool kconfig symbol:
config BRCMFMAC_SDIO
bool "SDIO bus interface support for FullMAC driver"
depends on MMC
allows BRCMFMAC_SDIO to be y even when MMC=m.
Is there a reasonable solution to this?
This causes many build errors:
drivers/built-in.o: In function `brcmf_sdio_assert_info':
dhd_sdio.c:(.text+0x39609b): undefined reference to `sdio_claim_host'
dhd_sdio.c:(.text+0x3960d9): undefined reference to `sdio_release_host'
drivers/built-in.o: In function `brcmf_sdio_readframes':
dhd_sdio.c:(.text+0x396a62): undefined reference to `sdio_claim_host'
dhd_sdio.c:(.text+0x396a9b): undefined reference to `sdio_release_host'
..."
This patch adds the appropriate logic in Kconfig to resolve
these issues. The solution was provided by Hauke Mehrtens.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The cw1200_spi driver tries to mirror the cw1200_sdio driver's lock
API, which relies on sdio_claim_host/sdio_release_host to serialize
hardware operations across multiple threads.
Unfortunately the implementation was flawed, as it lacked a way to wake
up the lock requestor when there was contention, often resulting in a
hang.
This problem was uncovered while trying to fix the
spi-transfers-in-interrupt-context BUG() corrected in the previous
patch. Many thanks to Dave Sizeburns for his assistance in fixing this.
Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When we get an interrupt from the hardware, the first thing the driver does
is tell the device to mask off the interrupt line. Unfortunately this
involves a SPI transaction in interrupt context. Some (most?) SPI
controllers perform the transfer asynchronously and try to sleep.
This is bad, and triggers a BUG().
So, work around this by using adding a hwbus hook for the cw1200 driver
core to call. The cw1200_spi driver translates this into
irq_disable()/irq_enable() calls instead, which can safely be called in
interrupt context.
Apparently the platforms I used to develop the cw1200_spi driver used
synchronous spi_sync() implementations, which is why this didn't surface
until now.
Many thanks to Dave Sizeburns for the inital bug report and his services
as a tester.
Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The only actual current lockref user (dcache) uses zero reference counts
even for perfectly live dentries, because it's a cache: there may not be
any users, but that doesn't mean that we want to throw away the dentry.
At the same time, the dentry cache does have a notion of a truly "dead"
dentry that we must not even increment the reference count of, because
we have pruned it and it is not valid.
Currently that distinction is not visible in the lockref itself, and the
dentry cache validation uses "lockref_get_or_lock()" to either get a new
reference to a dentry that already had existing references (and thus
cannot be dead), or get the dentry lock so that we can then verify the
dentry and increment the reference count under the lock if that
verification was successful.
That's all somewhat complicated.
This adds the concept of being "dead" to the lockref itself, by simply
using a count that is negative. This allows a usage scenario where we
can increment the refcount of a dentry without having to validate it,
and pushing the special "we killed it" case into the lockref code.
The dentry code itself doesn't actually use this yet, and it's probably
too late in the merge window to do that code (the dentry_kill() code
with its "should I decrement the count" logic really is pretty complex
code), but let's introduce the concept at the lockref level now.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The code got rewritten, but the comments got copied as-is from older
versions, and as a result the argument name in the comment didn't
actually match the code any more.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs pile 2 (of many) from Al Viro:
"Mostly Miklos' series this time"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
constify dcache.c inlined helpers where possible
fuse: drop dentry on failed revalidate
fuse: clean up return in fuse_dentry_revalidate()
fuse: use d_materialise_unique()
sysfs: use check_submounts_and_drop()
nfs: use check_submounts_and_drop()
gfs2: use check_submounts_and_drop()
afs: use check_submounts_and_drop()
vfs: check unlinked ancestors before mount
vfs: check submounts and drop atomically
vfs: add d_walk()
vfs: restructure d_genocide()
