that generates a fatal bus trap. Normally, the chips are setup to do
128 byte DMA bursts, but when on this CPU, they can only safely due
4-byte DMA bursts due to this bug. Details of the exact nature of the
bug are sketchy, but some can be found at
https://forum.openwrt.org/viewtopic.php?pid=70060 on pages 4, 5 and 6.
There's a small performance penalty associated with this workaround,
so it is only enabled when needed on the Atheros AR71xx platforms.
Unfortunately, this condition is impossible to detect at runtime
without MIPS specific ifdefs. Rather than cast an overly-broad net
like Linux/OpenWRT dues (which enables this workaround all the time on
MIPS32 platforms), we put this option in the kernel for just the
affected machines. Sam didn't like this aspect of the patch when he
reviewed it, and I'd love to hear sane proposals on how to fix it :)
Reviewed by: sam@
o rename the new variables to comply with the naming scheme
o move the new variables to an AR5212 specific struct
o use ahp when available
o revert to previous ts_flags check
available today.
This card is a low power 802.11bgn that only does 11n rates up to MCS 7
(that's 65 Mbps in 20Mhz mode and 135 in 40Mhz mode).
802.11n is not yet supported, but will be in the future.
The driver still has a problem regarding to the setting of txpower on
the card, so don't expect good performance yet. After fixing this
problem, an MFC is possible.
Special thanks to iXsystems and S Smirnov <tonve at yandex.ru> for help
with the purchase of a netbook with this card.
Sponsored by: iXsystems, Inc.
This is needed by the upcoming AR9285 support.
Information on the layout gathered from Linux ath9k.
Not yet connected to the build.
Tested by: Eugeny Dzhurinsky
inbound data waiting on a filedescriptor, such as a pipe or a socket,
for instance by using select(2), poll(2), kqueue(2), ioctl(FIONREAD)
etc.
But we have no way of finding out if written data have yet to be
disposed of, for instance, transmitted (and ack'ed!) to some remote
host, or read by the applicantion at the far end of the pipe.
The closest we get, is calling shutdown(2) on a TCP socket in
non-blocking mode, but this has the undesirable sideeffect of
preventing future communication.
Add a complement to FIONREAD, called FIONWRITE, which returns the
number of bytes not yet properly disposed of. Implement it for
all sockets.
Background:
A HTTP server will want to time out connections, if no new request
arrives within a certain period after the last transmitted response
has actually been sent (and ack'ed).
For a busy HTTP server, this timeout can be subsecond duration.
In order to signal to a load-balancer that the connection is truly
dead, TCP_RST will be the preferred method, as this avoids the need
for a RTT delay for FIN handshaking, with a client which, surprisingly
often, no longer at the remote IP number.
If a slow, distant client is being served a response which is big
enough to fill the window, but small enough to fit in the socket
buffer, the write(2) call will return immediately.
If the session timeout is armed at that time, all bytes in the
response may not have been transmitted by the time it fires.
FIONWRITE allows the timeout to check that no data is outstanding
on the connection, before it TCP_RST's it.
Input & Idea from: rwatson
Approved by: re (kib)
o add HAL_CAP_BSSIDMATCH to identify parts that have the support for
disabling bssid match
o honor capability for set/get rx filter
o use HAL_CAP_BSSIDMATCH in driver to decide whether to use the bssid
match disable or fall back to promisc mode
Reviewed by: rpaulo
Approved by: re (rwatson)
