timestamped TCP packets where FreeBSD will send DATA+FIN and
A W2K box will ack just the DATA portion. If this occurs
after FreeBSD has done a (NewReno) fast-retransmit and is
recovering it (dupacks > threshold) it triggers a case in
tcp_newreno_partial_ack() (tcp_newreno() in stable) where
tcp_output() is called with the expectation that the retransmit
timer will be reloaded. But tcp_output() falls through and
returns without doing anything, causing the persist timer to be
loaded instead. This causes the connection to hang until W2K gives up.
This occurs because in the case where only the FIN must be acked, the
'len' calculation in tcp_output() will be 0, a lot of checks will be
skipped, and the FIN check will also be skipped because it is designed
to handle FIN retransmits, not forced transmits from tcp_newreno().
The solution is to simply set TF_ACKNOW before calling tcp_output()
to absolute guarentee that it will run the send code and reset the
retransmit timer. TF_ACKNOW is already used for this purpose in other
cases.
For some unknown reason this patch also seems to greatly reduce
the number of duplicate acks received when Guido runs his tests over
a lossy network. It is quite possible that there are other
tcp_newreno{_partial_ack()} cases which were not generating the expected
output which this patch also fixes.
X-MFC after: Will be MFC'd after the freeze is over
of 1 so that it is not probed until after acpi0 is probed and attached.
- In legacy_probe(), return ENXIO if acpi0 is around and alive.
- nexus_attach() is now much simpler and just lets its child drivers do
all the work.
and attach routines have succeeded so that if they fail we can still use
the PnP BIOS to find ISA on-board devices. The fact that we do this here
is gross but fixing it properly involves a lot more work.
code path to fix a bug in the non USB_USE_SOFTINTR path that caused
the usb bus to hang and generally misbehave when devices were unplugged.
In the process though it also reduced the throughput of usb devices because
of a less than optimal implementation under FreeBSD.
This commit fixes the non USB_USE_SOFTINTR code in uhci and ohci
so that it works again, and switches back to using this code path.
The uhci code has been tested, but the ohci code hasn't. It's
essentially the same anyway and so I don't envisage any difficulties.
Code for uhci submitted by: Maksim Yevmenkin <myevmenk@exodus.net>
testing any modifications to them, they shouldn't even bother with
disklabels in the first place and they are just plain obsolete old
hardware which should be axed entirely before 5.0-R IMO.
Sponsored by: DARPA & NAI Labs.
from stopping another thread from completing a syscall, and this allows it to
release its resources etc. Probably more related commits to follow (at least
one I know of)
Initial concept by: julian, dillon
Submitted by: davidxu
device_t the same throughout kernel.
This is a very fine point of C which fortunatly does not make any
difference in normal circumstances but which due to the pervasiveness
of device_t in the kernel can make a lint barf a lot.
