Commit Graph

27243 Commits

Author SHA1 Message Date
David S. Miller 15986e1aad [TCP]: tcp_rcv_rtt_measure_ts() call in pure-ACK path is superfluous
We only want to take receive RTT mesaurements for data
bearing frames, here in the header prediction fast path
for a pure-sender, we know that we have a pure-ACK and
thus the checks in tcp_rcv_rtt_mesaure_ts() will not pass.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:16 -07:00
Stephen Hemminger 11dc1f36a6 [BRIDGE]: netlink interface for link management
Add basic netlink support to the Ethernet bridge. Including:
 * dump interfaces in bridges
 * monitor link status changes
 * change state of bridge port

For some demo programs see:
	http://developer.osdl.org/shemminger/prototypes/brnl.tar.gz

These are to allow building a daemon that does alternative
implementations of Spanning Tree Protocol.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:14 -07:00
Stephen Hemminger c090971326 [BRIDGE]: fix module startup error handling
Return address in use, if some other kernel code has the SAP.
Propogate out error codes from netfilter registration and unwind.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:12 -07:00
Stephen Hemminger 9ef513bed6 [BRIDGE]: optimize conditional in forward path
Small optimizations of bridge forwarding path.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:10 -07:00
Stephen Hemminger bc0e646796 [LLC]: add multicast support for datagrams
Allow mulitcast reception of datagrams (similar to UDP).
All sockets bound to the same SAP receive a clone.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:08 -07:00
Stephen Hemminger 8f182b494f [LLC]: allow applications to get copy of kernel datagrams
It is legal for an application to bind to a SAP that is also being
used by the kernel. This happens if the bridge module binds to the
STP SAP, and the user wants to have a daemon for STP as well.
It is possible to have kernel doing STP on one bridge, but
let application do RSTP on another bridge.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:06 -07:00
Stephen Hemminger 23dbe7912d [LLC]: use rcu_dereference on receive handler
The receive hander pointer might be modified during network changes
of protocol. So use rcu_dereference (only matters on alpha).

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:04 -07:00
Stephen Hemminger 29efcd2666 [LLC]: allow datagram recvmsg
LLC receive is broken for SOCK_DGRAM.
If an application does recv() on a datagram socket and there
is no data present, don't return "not connected". Instead, just
do normal datagram semantics.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:26:02 -07:00
Stephen Hemminger aecbd4e45c [LLC]: use more efficient ether address routines
Use more cache efficient Ethernet address manipulation functions
in etherdevice.h.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
2006-06-17 21:26:00 -07:00
Andrew Morton 17f3ae08b6 [I/OAT]: Do not use for_each_cpu().
for_each_cpu() is going away (and is gone in -mm).

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:58 -07:00
Chris Leech 1a2449a87b [I/OAT]: TCP recv offload to I/OAT
Locks down user pages and sets up for DMA in tcp_recvmsg, then calls
dma_async_try_early_copy in tcp_v4_do_rcv

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:56 -07:00
Chris Leech 9593782585 [I/OAT]: Add a sysctl for tuning the I/OAT offloaded I/O threshold
Any socket recv of less than this ammount will not be offloaded

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:54 -07:00
Chris Leech 624d116473 [I/OAT]: Make sk_eat_skb I/OAT aware.
Add an extra argument to sk_eat_skb, and make it move early copied
packets to the async_wait_queue instead of freeing them.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:52 -07:00
Chris Leech 0e4b4992b8 [I/OAT]: Rename cleanup_rbuf to tcp_cleanup_rbuf and make non-static
Needed to be able to call tcp_cleanup_rbuf in tcp_input.c for I/OAT

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:50 -07:00
Chris Leech 97fc2f0848 [I/OAT]: Structure changes for TCP recv offload to I/OAT
Adds an async_wait_queue and some additional fields to tcp_sock, and a
dma_cookie_t to sk_buff.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:48 -07:00
Chris Leech de5506e155 [I/OAT]: Utility functions for offloading sk_buff to iovec copies
Provides for pinning user space pages in memory, copying to iovecs,
and copying from sk_buffs including fragmented and chained sk_buffs.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:25:46 -07:00
Chris Leech db21733488 [I/OAT]: Setup the networking subsystem as a DMA client
Attempts to allocate per-CPU DMA channels

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:24:58 -07:00
David S. Miller 57c651f74c [I/OAT]: Move PCI_DEVICE_ID_INTEL_IOAT to linux/pci_ids.h
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:18:50 -07:00
David S. Miller 6b00c92c4b [I/OAT]: ioatdma.c needs linux/dma-mapping.h
For DMA_*_MASK defines.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:18:48 -07:00
Chris Leech 0bbd5f4e97 [I/OAT]: Driver for the Intel(R) I/OAT DMA engine
Adds a new ioatdma driver

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:18:46 -07:00
Chris Leech c13c8260da [I/OAT]: DMA memcpy subsystem
Provides an API for offloading memory copies to DMA devices

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-17 21:18:43 -07:00
Linus Torvalds 427abfa28a Linux v2.6.17
Being named "Crazed Snow-Weasel" instills a lot of confidence in this
release, so I'm sure this will be one of the better ones.
2006-06-17 18:49:35 -07:00
Arnd Bergmann ce221982e0 [PATCH] powerpc: enable CPU_FTR_CI_LARGE_PAGE for cell
Reflect the fact that the Cell Broadband Engine supports 64k
pages by adding the bit to the CPU features.

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:56:24 -07:00
Arnd Bergmann 19242b2407 [PATCH] powerpc: Fix 64k pages on non-partitioned machines
The page size encoding passed to tlbie is incorrect for new-style
large pages.  This fixes it.  This doesn't affect anything on older
machines because mmu_psize_defs[psize].penc (the page size encoding)
is 0 for 4k and 16M pages (the two are distinguished by a separate "is
a large page" bit).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:56:24 -07:00
Oleg Nesterov f53ae1dc34 [PATCH] arm_timer: remove a racy and obsolete PF_EXITING check
arm_timer() checks PF_EXITING to prevent BUG_ON(->exit_state)
in run_posix_cpu_timers().

However, for some reason it does so only for CPUCLOCK_PERTHREAD
case (which is imho wrong).

Also, this check is not reliable, PF_EXITING could be set on
another cpu without any locks/barriers just after the check,
so it can't prevent from attaching the timer to the exiting
task.

The previous patch makes this check unneeded.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:52:13 -07:00
Oleg Nesterov 30f1e3dd8c [PATCH] run_posix_cpu_timers: remove a bogus BUG_ON()
do_exit() clears ->it_##clock##_expires, but nothing prevents
another cpu to attach the timer to exiting process after that.
arm_timer() tries to protect against this race, but the check
is racy.

After exit_notify() does 'write_unlock_irq(&tasklist_lock)' and
before do_exit() calls 'schedule() local timer interrupt can find
tsk->exit_state != 0. If that state was EXIT_DEAD (or another cpu
does sys_wait4) interrupted task has ->signal == NULL.

At this moment exiting task has no pending cpu timers, they were
cleanuped in __exit_signal()->posix_cpu_timers_exit{,_group}(),
so we can just return from irq.

John Stultz recently confirmed this bug, see

	http://marc.theaimsgroup.com/?l=linux-kernel&m=115015841413687

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:52:13 -07:00
Oleg Nesterov 8f17fc20bf [PATCH] check_process_timers: fix possible lockup
If the local timer interrupt happens just after do_exit() sets PF_EXITING
(and before it clears ->it_xxx_expires) run_posix_cpu_timers() will call
check_process_timers() with tasklist_lock + ->siglock held and

	check_process_timers:

		t = tsk;
		do {
			....

			do {
				t = next_thread(t);
			} while (unlikely(t->flags & PF_EXITING));
		} while (t != tsk);

the outer loop will never stop.

Actually, the window is bigger.  Another process can attach the timer
after ->it_xxx_expires was cleared (see the next commit) and the 'if
(PF_EXITING)' check in arm_timer() is racy (see the one after that).

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:52:13 -07:00
Stephen Hemminger 88d113601c [PATCH] sky2: netconsole suspend/resume interaction
A couple of fixes that should prevent crashes when using netconsole and
suspend/resume. First, netconsole poll routine shouldn't run unless the
device is up; second, the NAPI poll should be disabled during suspend.

This is only an issue on sky2, because it has to have one NAPI poll
routine for both ports on dual port boards. Normal drivers use
netif_rx_schedule_prep and that checks for netif_running.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:52:12 -07:00
Jens Axboe 991721572e [PATCH] Fix missing ret assignment in __bio_map_user() error path
If get_user_pages() returns less pages than what we asked for, we jump
to out_unmap which will return ERR_PTR(ret).  But ret can contain a
positive number just smaller than local_nr_pages, so be sure to set it
to -EFAULT always.

Problem found and diagnosed by Damien Le Moal <damien@sdl.hitachi.co.jp>

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:52:12 -07:00
Jens Axboe 16070428d3 [PATCH] fix cdrom open
Some time ago the cdrom open routine was changed so that we call the
driver's open routine before checking to see if it is read only.  However,
if we discovered that a read write open was not possible and the open
flags required a writable open, we just returned -EROFS without calling
the driver's release routine.   This seems to work for most cdrom drivers,
but breaks the Powerpc iSeries virtual cdrom rather badly.

This just inserts the release call in the error path to balance the call
to "->open()" done by "open_for_data()".

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-17 10:44:26 -07:00
Jens Axboe 553698f944 [PATCH] cfq-iosched: fix crash in do_div()
We don't clear the seek stat values in cfq_alloc_io_context(), and if
->seek_mean is unlucky enough to be set to -36 by chance, the first
invocation of cfq_update_io_seektime() will oops with a divide by zero
in do_div().

Just memset the entire cic instead of filling invididual values
independently.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-14 10:22:16 -07:00
Kirill Korotaev 9cedc194a7 [PATCH] Return error in case flock_lock_file failure
If flock_lock_file() failed to allocate flock with locks_alloc_lock()
then "error = 0" is returned. Need to return some non-zero.

Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-14 08:59:44 -07:00
Stephen Hemminger eb35cf60e4 [PATCH] sky2: stop/start hardware idle timer on suspend/resume
The resume bug was caused not by an early interrupt but because the idle
timeout was not being stopped on suspend.  Also disable hardware IRQ's
on suspend.  Will need to revisit this with hotplug?

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-13 13:16:41 -07:00
Stephen Hemminger 8ab8fca207 [PATCH] sky2: save/restore base hardware irq during suspend/resume
The hardware should be fully shut off during suspend, and the base
irq mask restored during resume.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-13 13:16:41 -07:00
Stephen Hemminger 26ec43f132 [PATCH] sky2: fix hotplug detect during poll
If the poll routine detects no hardware available, it needs to dequeue
it self from the network poll list. Linus didn't understand NAPI.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-13 13:16:41 -07:00
Stephen Hemminger f05267e7de [PATCH] sky2: don't hard code number of ports
It is cleaner, to not loop over both ports if only one exists.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-13 13:16:41 -07:00
Stephen Hemminger 2ccc99b7b7 [PATCH] sky2: set_power_state should be void
The set power state function is cleaner if it doesn't return anything.
The only caller that could fail is in suspend() and it can check the argument
there.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-13 13:16:40 -07:00
Randy Dunlap 5e625b0844 [PATCH] alpha: generic hweight build fix
From: Randy Dunlap <rdunlap@xenotime.net>

According to include/asm-alpha/bitops.h, only ALPHA_EV67 has hardware
hweight support, so ALPHA_EV6 needs to use GENERIC_HWEIGHT.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Ernst Herzberg <earny@net4u.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-12 15:17:53 -07:00
Sergey Vlasov 86bc843a26 [PATCH] tmpfs: Decrement i_nlink correctly in shmem_rmdir()
shmem_rmdir() must undo the increment of i_nlink done in
shmem_get_inode() for directories, otherwise at least
IN_DELETE_SELF inotify event generation is broken.

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-12 14:29:04 -07:00
Robin H. Johnson cfd95a9cf5 [PATCH] tmpfs: time granularity fix for [acm]time going backwards
I noticed a strange behavior in a tmpfs file system the other day, while
building packages - occasionally, and seemingly at random, make decided to
rebuild a target. However, only on tmpfs.

A file would be created, and if checked, it had a sub-second timestamp.
However, after an utimes related call where sub-seconds should be set, they
were zeroed instead. In the case that a file was created, and utimes(...,NULL)
was used on it in the same second, the timestamp on the file moved backwards.

After some digging, I found that this was being caused by tmpfs not having a
time granularity set, thus inheriting the default 1 second granularity.

Hugh adds: yes, we missed tmpfs when the s_time_gran mods went into 2.6.11.
Unfortunately, the granularity of CURRENT_TIME, often used in filesystems,
does not match the default granularity set by alloc_super.  A few more such
discrepancies have been found, but this is the most important to fix now.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-12 13:55:52 -07:00
Linus Torvalds 5f856e8bdc Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
  [SPARC64]: Do not double-export sys_close() when CONFIG_SOLARIS_EMUL_MODULE
2006-06-12 13:46:43 -07:00
Linus Torvalds a3b5960ebd Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [IPV4]: Increment ipInHdrErrors when TTL expires.
  [TCP]: continued: reno sacked_out count fix
  [DCCP] Ackvec: fix soft lockup in ackvec handling code
2006-06-12 13:46:27 -07:00
Linus Torvalds 37b0d1dedc Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] Fix Integrator and Versatile interrupt initialisation
  [ARM] 3546/1: PATCH: subtle lost interrupts bug on i.MX
  [ARM] 3547/1: PXA-OHCI: Allow platforms to specify a power budget
  [ARM] Fix Neponset IRQ handling
2006-06-12 13:45:41 -07:00
Weidong 42d1d52e69 [IPV4]: Increment ipInHdrErrors when TTL expires.
Signed-off-by: Weidong <weid@nanjing-fnst.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-12 13:09:59 -07:00
Linus Torvalds d374c1c128 [sky2] Fix sky2 network driver suspend/resume
This fixes two independent problems: it would not save the PCI state on
suspend (and thus try to resume a nonexistent state on resume), and
while shut off, if an interrupt happened on the same shared irq, the irq
handler would react very badly to the interrupt status being an invalid
all-ones state.

Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-12 12:53:27 -07:00
Linus Torvalds 0e838b72d5 Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [PATCH] sata_mv: grab host lock inside eng_timeout
2006-06-12 07:47:04 -07:00
Aki M Nyrhinen 79320d7e14 [TCP]: continued: reno sacked_out count fix
From: Aki M Nyrhinen <anyrhine@cs.helsinki.fi>

IMHO the current fix to the problem (in_flight underflow in reno)
is incorrect.  it treats the symptons but ignores the problem. the
problem is timing out packets other than the head packet when we
don't have sack. i try to explain (sorry if explaining the obvious).

with sack, scanning the retransmit queue for timed out packets is
fine because we know which packets in our retransmit queue have been
acked by the receiver.

without sack, we know only how many packets in our retransmit queue the
receiver has acknowledged, but no idea which packets.

think of a "typical" slow-start overshoot case, where for example
every third packet in a window get lost because a router buffer gets
full.

with sack, we check for timeouts on those every third packet (as the
rest have been sacked). the packet counting works out and if there
is no reordering, we'll retransmit exactly the packets that were 
lost.

without sack, however, we check for timeout on every packet and end up
retransmitting consecutive packets in the retransmit queue. in our
slow-start example, 2/3 of those retransmissions are unnecessary. these
unnecessary retransmissions eat the congestion window and evetually
prevent fast recovery from continuing, if enough packets were lost.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-11 21:18:56 -07:00
Andrea Bittau afec35e3fe [DCCP] Ackvec: fix soft lockup in ackvec handling code
A soft lockup existed in the handling of ack vector records.
Specifically, when a tail of the list of ack vector records was
removed, it was possible to end up iterating infinitely on an element
of the tail.

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-11 21:08:03 -07:00
David S. Miller ccefb5f3f6 [SPARC64]: Do not double-export sys_close() when CONFIG_SOLARIS_EMUL_MODULE
It is already exported by fs/open.c

Noticed by Ben Collins.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-11 21:05:25 -07:00
Paul Mackerras 289a1e995e [PATCH] Fix for the PPTP hangs that have been reported
People have been reporting that PPP connections over ptys, such as
used with PPTP, will hang randomly when transferring large amounts of
data, for instance in http://bugzilla.kernel.org/show_bug.cgi?id=6530.
I have managed to reproduce the problem, and the patch below fixes the
actual cause.

The problem is not in fact in ppp_async.c but in n_tty.c.  What
happens is that when pptp reads from the pty, we call read_chan() in
drivers/char/n_tty.c on the master side of the pty.  That copies all
the characters out of its buffer to userspace and then calls
check_unthrottle(), which calls the pty unthrottle routine, which
calls tty_wakeup on the slave side, which calls ppp_asynctty_wakeup,
which calls tasklet_schedule.  So far so good.  Since we are in
process context, the tasklet runs immediately and calls
ppp_async_process(), which calls ppp_async_push, which calls the
tty->driver->write function to send some more output.

However, tty->driver->write() returns zero, because the master
tty->receive_room is still zero.  We haven't returned from
check_unthrottle() yet, and read_chan() only updates tty->receive_room
_after_ calling check_unthrottle.  That means that the driver->write
call in ppp_async_process() returns 0.  That would be fine if we were
going to get a subsequent wakeup call, but we aren't (we just had it,
and the buffer is now empty).

The solution is for n_tty.c to update tty->receive_room _before_
calling the driver unthrottle routine.  The patch below does this.
With this patch I was able to transfer a 900MB file over a PPTP
connection (taking about 25 minutes), whereas without the patch the
connection would always stall in under a minute.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-11 20:40:39 -07:00