| Age | Commit message (Collapse) | Author |
|---|
|
We forgot to use __GFP_HIGHMEM in several __vmalloc() calls.
In ceph, add the missing flag.
In fib_trie.c, xfrm_hash.c and request_sock.c, using vzalloc() is
cleaner and allows using HIGHMEM pages as well.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
alloc_one_pg_vec_page() is supposed to return zeroed memory, so use
vzalloc() instead of vmalloc()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
We call svc_xprt_enqueue() after something happens which we think may
require handling from a server thread. To avoid such events being lost,
svc_xprt_enqueue() must guarantee that there will be a svc_serv() call
from a server thread following any such event. It does that by either
waking up a server thread itself, or checking that XPT_BUSY is set (in
which case somebody else is doing it).
But the check of XPT_BUSY could occur just as someone finishes
processing some other event, and just before they clear XPT_BUSY.
Therefore it's important not to clear XPT_BUSY without subsequently
doing another svc_export_enqueue() to check whether the xprt should be
requeued.
The xpo_wspace() check in svc_xprt_enqueue() breaks this rule, allowing
an event to be missed in situations like:
data arrives
call svc_tcp_data_ready():
call svc_xprt_enqueue():
set BUSY
find no write space
svc_reserve():
free up write space
call svc_enqueue():
test BUSY
clear BUSY
So, instead, check wspace in the same places that the state flags are
checked: before taking BUSY, and in svc_receive().
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
|
|
Neil Brown had to explain to me why we do this here; record the answer
for posterity.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
|
|
There's no need to be fooling with XPT_BUSY now that all the threads
are gone.
The list_del_init() here could execute at the same time as the
svc_xprt_enqueue()'s list_add_tail(), with undefined results. We don't
really care at this point, but it might result in a spurious
list-corruption warning or something.
And svc_close() isn't adding any value; just call svc_delete_xprt()
directly.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
|
|
Follow up on b48fa6b99100dc7772af3cd276035fcec9719ceb by moving all the
svc_xprt_received() calls for the main xprt to one place. The clearing
of XPT_BUSY here is critical to the correctness of the server, so I'd
prefer it to be obvious where we do it.
The only substantive result is moving svc_xprt_received() after
svc_receive_deferred(). Other than a (likely insignificant) delay
waking up the next thread, that should be harmless.
Also reshuffle the exit code a little to skip a few other steps that we
don't care about the in the svc_delete_xprt() case.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
|
|
There's no harm to doing this, since the only caller will immediately
call svc_enqueue() afterwards, ensuring we don't miss the remaining
deferred requests just because XPT_DEFERRED was briefly cleared.
But why not just do this the simple way?
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: fix readdir EOVERFLOW on 32-bit archs
ceph: fix frag offset for non-leftmost frags
ceph: fix dangling pointer
ceph: explicitly specify page alignment in network messages
ceph: make page alignment explicit in osd interface
ceph: fix comment, remove extraneous args
ceph: fix update of ctime from MDS
ceph: fix version check on racing inode updates
ceph: fix uid/gid on resent mds requests
ceph: fix rdcache_gen usage and invalidate
ceph: re-request max_size if cap auth changes
ceph: only let auth caps update max_size
ceph: fix open for write on clustered mds
ceph: fix bad pointer dereference in ceph_fill_trace
ceph: fix small seq message skipping
Revert "ceph: update issue_seq on cap grant"
|
|
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (31 commits)
net: fix kernel-doc for sk_filter_rcu_release
be2net: Fix to avoid firmware update when interface is not open.
netfilter: fix IP_VS dependencies
net: irda: irttp: sync error paths of data- and udata-requests
ipv6: Expose reachable and retrans timer values as msecs
ipv6: Expose IFLA_PROTINFO timer values in msecs instead of jiffies
3c59x: fix build failure on !CONFIG_PCI
ipg.c: remove id [SUNDANCE, 0x1021]
net: caif: spi: fix potential NULL dereference
ath9k_htc: Avoid setting QoS control for non-QoS frames
net: zero kobject in rx_queue_release
net: Fix duplicate volatile warning.
MAINTAINERS: Add stmmac maintainer
bonding: fix a race in IGMP handling
cfg80211: fix can_beacon_sec_chan, reenable HT40
gianfar: fix signedness issue
net: bnx2x: fix error value sign
8139cp: fix checksum broken
r8169: fix checksum broken
rds: Integer overflow in RDS cmsg handling
...
|
|
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
drivers/net/bonding/bond_main.c
net/core/net-sysfs.c
net/ipv6/addrconf.c
|
|
Routing doesn't use the socket data and is protected by x25_route_list_lock
Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Push down the bkl in the ioctls so they can be removed one at a time.
Signed-off-by: Andrew Hendry <andrew.hendry@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
At compile time, we can replace the DIV_K instruction (divide by a
constant value) by a reciprocal divide.
At exec time, the expensive divide is replaced by a multiply, a less
expensive operation on most processors.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Starting the translated instruction to 1 instead of 0 allows us to
remove one descrement at check time and makes codes[] array init
cleaner.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Remove pc variable to avoid arithmetic to compute fentry at each filter
instruction. Jumps directly manipulate fentry pointer.
As the last instruction of filter[] is guaranteed to be a RETURN, and
all jumps are before the last instruction, we dont need to check filter
bounds (number of instructions in filter array) at each iteration, so we
remove it from sk_run_filter() params.
On x86_32 remove f_k var introduced in commit 57fe93b374a6b871
(filter: make sure filters dont read uninitialized memory)
Note : We could use a CONFIG_ARCH_HAS_{FEW|MANY}_REGISTERS in order to
avoid too many ifdefs in this code.
This helps compiler to use cpu registers to hold fentry and A
accumulator.
On x86_32, this saves 401 bytes, and more important, sk_run_filter()
runs much faster because less register pressure (One less conditional
branch per BPF instruction)
# size net/core/filter.o net/core/filter_pre.o
text data bss dec hex filename
2948 0 0 2948 b84 net/core/filter.o
3349 0 0 3349 d15 net/core/filter_pre.o
on x86_64 :
# size net/core/filter.o net/core/filter_pre.o
text data bss dec hex filename
5173 0 0 5173 1435 net/core/filter.o
5224 0 0 5224 1468 net/core/filter_pre.o
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Fix kernel-doc warning for sk_filter_rcu_release():
Warning(net/core/filter.c:586): missing initial short description on line:
* sk_filter_rcu_release: Release a socket filter by rcu_head
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
When NF_CONNTRACK is enabled, IP_VS uses conntrack symbols.
Therefore IP_VS can't be linked statically when conntrack
is built modular.
Reported-by: Justin P. Mattock <justinmattock@gmail.com>
Tested-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
irttp_data_request() returns meaningful errorcodes, while irttp_udata_request()
just returns -1 in similar situations. Sync the two and the loglevels of the
accompanying output.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Expose reachable and retrans timer values in msecs instead of jiffies.
Both timer values are already exposed as msecs in the neighbour table
netlink interface.
The creation timestamp format with increased precision is kept but
cleaned up.
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6
|
|
Extend nl80211 to report an exponential weighted moving average (EWMA) of the
signal value. Since the signal value usually fluctuates between different
packets, an average can be more useful than the value of the last packet.
This uses the recently added generic EWMA library function.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
IFLA_PROTINFO exposes timer related per device settings in jiffies.
Change it to expose these values in msecs like the sysctl interface
does.
I did not find any users of IFLA_PROTINFO which rely on any of these
values and even if there are, they are likely already broken because
there is no way for them to reliably convert such a value to another
time format.
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
IGMP allocates MTU sized skbs. This may fail for large MTU (order-2
allocations), so add a fallback to try lower sizes.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
BPF_S_* are used internally, should not be exposed to the others.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Since repeating u16 value to u8 value conversion using switch() clause's
case statement is wasteful, this patch introduces u16 to u8 mapping table
and removes most of case statements. As a result, the size of net/core/filter.o
is reduced by about 29% on x86.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Add option to set skb priority to pktgen. Useful for testing
QOS features. Also by running pktgen on the vlan device the
qdisc on the real device can be tested.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
netif_set_real_num_rx_queues() can decrement and increment
the number of rx queues. For example ixgbe does this as
features and offloads are toggled. Presumably this could
also happen across down/up on most devices if the available
resources changed (cpu offlined).
The kobject needs to be zero'd in this case so that the
state is not preserved across kobject_put()/kobject_init_and_add().
This resolves the following error report.
ixgbe 0000:03:00.0: eth2: NIC Link is Up 10 Gbps, Flow Control: RX/TX
kobject (ffff880324b83210): tried to init an initialized object, something is seriously wrong.
Pid: 1972, comm: lldpad Not tainted 2.6.37-rc18021qaz+ #169
Call Trace:
[<ffffffff8121c940>] kobject_init+0x3a/0x83
[<ffffffff8121cf77>] kobject_init_and_add+0x23/0x57
[<ffffffff8107b800>] ? mark_lock+0x21/0x267
[<ffffffff813c6d11>] net_rx_queue_update_kobjects+0x63/0xc6
[<ffffffff813b5e0e>] netif_set_real_num_rx_queues+0x5f/0x78
[<ffffffffa0261d49>] ixgbe_set_num_queues+0x1c6/0x1ca [ixgbe]
[<ffffffffa0262509>] ixgbe_init_interrupt_scheme+0x1e/0x79c [ixgbe]
[<ffffffffa0274596>] ixgbe_dcbnl_set_state+0x167/0x189 [ixgbe]
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This fixes whitespace noise introduced in commit "dccp ccid-2: Algorithm to
update buffer state", 5753fdfe8bd8e9a2ff9e5af19b0ffc78bfcd502a, 14 Nov 2010.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Instead of iterating in_dev->mc_list from bonding driver, its better
to call a helper function provided by igmp.c
Details of implementation (locking) are private to igmp code.
ip_mc_rejoin_group(struct ip_mc_list *im) becomes
ip_mc_rejoin_groups(struct in_device *in_dev);
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This follows wireless-testing 9236d838c920e90708570d9bbd7bb82d30a38130
("cfg80211: fix extension channel checks to initiate communication") and
fixes accidental case fall-through. Without this fix, HT40 is entirely
blocked.
Signed-off-by: Mark Mentovai <mark@moxienet.com>
Cc: stable@kernel.org
Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
The code to handle powersaving stations has a race:
when the powersave flag is lifted from a station,
we could transmit a packet that is being processed
for TX at the same time right away, even if there
are other frames queued for it. This would cause
frame reordering. To fix this, lift the flag only
under the appropriate lock that blocks TX.
Additionally, the code to allow drivers to block a
station while frames for it are on the HW queue is
never re-enabled the station, so traffic would get
stuck indefinitely. Fix this by clearing the flag
for this appropriately.
Finally, as an optimisation, don't do anything if
the driver unblocks an already unblocked station.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
In many places we've just hardcoded the
AC numbers -- which is a relic from the
original mac80211 (d80211). Add constants
for them so we know what we're talking
about.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
snprintf() returns number of bytes that were copied if there is no overflow.
This code uses return value as number of copied bytes. Theoretically format
string '%lu.%09lu %pI4:%u %pI4:%u %d %#x %#x %u %u %u %u\n' may be expanded
up to 163 bytes. In reality tv.tv_sec is just few bytes instead of 20, 2 ports
are just 5 bytes each instead of 10, length is 5 bytes instead of 10. The rest
is an unstrusted input. Theoretically if tv_sec is big then copy_to_user() would
overflow tbuf.
tbuf was increased to fit in 163 bytes. snprintf() is used to follow return
value semantic.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
netif_set_real_num_rx_queues() can decrement and increment
the number of rx queues. For example ixgbe does this as
features and offloads are toggled. Presumably this could
also happen across down/up on most devices if the available
resources changed (cpu offlined).
The kobject needs to be zero'd in this case so that the
state is not preserved across kobject_put()/kobject_init_and_add().
This resolves the following error report.
ixgbe 0000:03:00.0: eth2: NIC Link is Up 10 Gbps, Flow Control: RX/TX
kobject (ffff880324b83210): tried to init an initialized object, something is seriously wrong.
Pid: 1972, comm: lldpad Not tainted 2.6.37-rc18021qaz+ #169
Call Trace:
[<ffffffff8121c940>] kobject_init+0x3a/0x83
[<ffffffff8121cf77>] kobject_init_and_add+0x23/0x57
[<ffffffff8107b800>] ? mark_lock+0x21/0x267
[<ffffffff813c6d11>] net_rx_queue_update_kobjects+0x63/0xc6
[<ffffffff813b5e0e>] netif_set_real_num_rx_queues+0x5f/0x78
[<ffffffffa0261d49>] ixgbe_set_num_queues+0x1c6/0x1ca [ixgbe]
[<ffffffffa0262509>] ixgbe_init_interrupt_scheme+0x1e/0x79c [ixgbe]
[<ffffffffa0274596>] ixgbe_dcbnl_set_state+0x167/0x189 [ixgbe]
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Use the macros defined for the members of flowi to clean the code up.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
In rds_cmsg_rdma_args(), the user-provided args->nr_local value is
restricted to less than UINT_MAX. This seems to need a tighter upper
bound, since the calculation of total iov_size can overflow, resulting
in a small sock_kmalloc() allocation. This would probably just result
in walking off the heap and crashing when calling rds_rdma_pages() with
a high count value. If it somehow doesn't crash here, then memory
corruption could occur soon after.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
IPv6 already exposes some address family data via netlink in the
IFLA_PROTINFO attribute if RTM_GETLINK request is sent with the
address family set to AF_INET6. We take over this format and
reuse all the code.
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Implements the AF_INET link address family exposing the per
device configuration settings via netlink using the attribute
IFLA_INET_CONF.
The format of IFLA_INET_CONF differs depending on the direction
the attribute is sent. The attribute sent by the kernel consists
of a u32 array, basically a 1:1 copy of in_device->cnf.data[].
The attribute expected by the kernel must consist of a sequence
of nested u32 attributes, each representing a change request,
e.g.
[IFLA_INET_CONF] = {
[IPV4_DEVCONF_FORWARDING] = 1,
[IPV4_DEVCONF_NOXFRM] = 0,
}
libnl userspace API documentation and example available from:
http://www.infradead.org/~tgr/libnl/doc-git/group__link__inet.html
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Each net_device contains address family specific data such as
per device settings and statistics. We already expose this data
via procfs/sysfs and partially netlink.
The netlink method requires the requester to send one RTM_GETLINK
request for each address family it wishes to receive data of
and then merge this data itself.
This patch implements a new API which combines all address family
specific link data in a new netlink attribute IFLA_AF_SPEC.
IFLA_AF_SPEC contains a sequence of nested attributes, one for each
address family which in turn defines the structure of its own
attribute. Example:
[IFLA_AF_SPEC] = {
[AF_INET] = {
[IFLA_INET_CONF] = ...,
},
[AF_INET6] = {
[IFLA_INET6_FLAGS] = ...,
[IFLA_INET6_CONF] = ...,
}
}
The API also allows for address families to implement a function
which parses the IFLA_AF_SPEC attribute sent by userspace to
implement address family specific link options.
Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The current tcp_connect code completely ignores errors from sending an skb.
This makes sense in many situations (like -ENOBUFFS) but I want to be able to
immediately fail connections if they are denied by the SELinux netfilter hook.
Netfilter does not normally return ECONNREFUSED when it drops a packet so we
respect that error code as a final and fatal error that can not be recovered.
Based-on-patch-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
SELinux would like to pass certain fatal errors back up the stack. This patch
implements the generic netfilter support for this functionality.
Based-on-patch-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
Chipsets with hardware based connection monitoring need to autonomically
send directed probe-request frames to the AP (in the event of beacon loss,
for example.)
For the hardware to be able to do this, it requires a template for the frame
to transmit to the AP, filled in with the BSSID and SSID of the AP, but also
the supported rate IE's.
This patch adds a function to mac80211, which allows the hardware driver to
fetch this template after association, so it can be configured to the hardware.
Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
Allow antenna configuration by calling driver's function for it.
We disallow antenna configuration if the wiphy is already running, mainly to
make life easier for 802.11n drivers which need to recalculate HT capabilites.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
|
Allow setting of TX and RX antennas configuration via nl80211.
The antenna configuration is defined as a bitmap of allowed antennas to use.
This API can be used to mask out antennas which are not attached or should not
be used for other reasons like regulatory concerns or special setups.
Separate bitmaps are used for RX and TX to allow configuring different antennas
for receiving and transmitting. Each bitmap is 32 bit long, each bit
representing one antenna, starting with antenna 1 at the first bit. If an
antenna bit is set, this means the driver is allowed to use this antenna for RX
or TX respectively; if the bit is not set the hardware is not allowed to use
this antenna.
Using bitmaps has the benefit of allowing for a flexible configuration
interface which can support many different configurations and which can be used
for 802.11n as well as non-802.11n devices. Instead of relying on some hardware
specific assumptions, drivers can use this information to know which antennas
are actually attached to the system and derive their capabilities based on
that.
802.11n devices should enable or disable chains, based on which antennas are
present (If all antennas belonging to a particular chain are disabled, the
entire chain should be disabled). HT capabilities (like STBC, TX Beamforming,
Antenna selection) should be calculated based on the available chains after
applying the antenna masks. Should a 802.11n device have diversity antennas
attached to one of their chains, diversity can be enabled or disabled based on
the antenna information.
Non-802.11n drivers can use the antenna masks to select RX and TX antennas and
to enable or disable antenna diversity.
While covering chainmasks for 802.11n and the standard "legacy" modes "fixed
antenna 1", "fixed antenna 2" and "diversity" this API also allows more rare,
but useful configurations as follows:
1) Send on antenna 1, receive on antenna 2 (or vice versa). This can be used to
have a low gain antenna for TX in order to keep within the regulatory
constraints and a high gain antenna for RX in order to receive weaker signals
("speak softly, but listen harder"). This can be useful for building long-shot
outdoor links. Another usage of this setup is having a low-noise pre-amplifier
on antenna 1 and a power amplifier on the other antenna. This way transmit
noise is mostly kept out of the low noise receive channel.
(This would be bitmaps: tx 1 rx 2).
2) Another similar setup is: Use RX diversity on both antennas, but always send
on antenna 1. Again that would allow us to benefit from a higher gain RX
antenna, while staying within the legal limits.
(This would be: tx 0 rx 3).
3) And finally there can be special experimental setups in research and
development even with pre 802.11n hardware where more than 2 antennas are
available. It's good to keep the API simple, yet flexible.
Signed-off-by: Bruno Randolf <br1@einfach.org>
--
v7: Made bitmasks 32 bit wide and rebased to latest wireless-testing.
Signed-off-by: John W. Linville <linville@tuxdriver.com>
|
