Commit graph

98458 commits

Author SHA1 Message Date
Alex Deucher
5e35eff13f drm/radeon: use DSTCACHE_CTLSTAT rather than RB2D_DSTCACHE_CTLSTAT
According to the hw guys, you should use DSTCACHE_CTLSTAT to flush
the 2D dst cache rather than RB2D_DSTCACHE_CTLSTAT.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 12:39:23 +10:00
Alex Deucher
5cfb695607 drm/radeon: switch IGP gart to use radeon_write_agp_base()
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 12:38:29 +10:00
Dennis Kasprzyk
7ecabc53a2 drm/radeon: Restore sw interrupt on resume
Fixes performance drop after suspend/resume on some systems.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 12:36:55 +10:00
Dave Airlie
70b13d510f drm/r500: add support for AGP based cards.
AGP registers weren't programmed properly for r500 cards.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:40:44 +10:00
Roland Scheidegger
9156cf09f5 drm/radeon: fix texture uploads with large 3d textures (bug 13980)
Texture uploads could hit the blitter coordinate limit, adjust the texture
offset when uploading the pieces. Make sure to check the end address of the
upload too.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:36:04 +10:00
Dave Airlie
c0beb2a723 drm/radeon: add initial r500 support.
This contains all the command buffer processing for the r500 cards.
It doesn't yet contain vblank support.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:40 +10:00
Alex Deucher
5b92c4045e drm/radeon: init pipe setup in kernel code.
This inits the card pipes in the kernel and lets userspace getparam
the correct setup.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:40 +10:00
Alex Deucher
d396db321b drm/radeon: fixup radeon_do_engine_reset
Cleanup do engine reset for different chip families.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:39 +10:00
Alex Deucher
259434accc drm/radeon: fix pixcache and purge/cache flushing registers
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:39 +10:00
Alex Deucher
d7463eb41d drm/radeon: write AGP_BASE_2 on chips that support it.
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:39 +10:00
Alex Deucher
45e519052e drm/radeon: merge IGP chip setup and fixup RS400 vs RS480 support
We only support RS480 (AMD based IGP) at the moment not
RS400 (Intel based IGP) ones.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:39 +10:00
Alex Deucher
2735977b12 drm/radeon: IGP clean up register and magic numbers.
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:39 +10:00
Dave Airlie
3722bfc607 drm/rs690: set base 2 to 0.
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:39 +10:00
Dave Airlie
fa0d71b967 drm/rs690: set all of gart base address.
Docs state bits 4-11 maps to bits 32-39 of the 40-bit range

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:39 +10:00
Alex Deucher
9f18409ea3 radeon: add production microcode from AMD
This adds production microcode for r100->r500 from AMD.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:38 +10:00
Dave Airlie
7ec700fcaf drm: pcigart use proper pci map interfaces.
Switch to using more correct pci dma mapping interfaces.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 11:27:23 +10:00
Tejun Heo
9a3b103c27 ahci: sis can't do PMP
From: Piter PUNK <piterpunk@slackware.com>

SiS AHCIs say they can do PMP but can't and fail detection if SRST w/
pmp==15 is used.  Turn off PMP support.

tj: added patch description, adapted patch to #upstream-fixes and
    renamed board_ahci_sis to board_ahci_nopmp.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-18 20:56:58 -04:00
Dave Airlie
9516b030b4 agp: more boolean conversions.
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 10:42:17 +10:00
Tejun Heo
040dee53a7 ata_piix: add TECRA M4 to broken suspend list
TOSHIBA also used "TECRA M4" in additon to "Tecra M4", add it.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-18 20:28:17 -04:00
Ben Dooks
cc18e0fea7 LIBATA: Add HAVE_PATA_PLATFORM to select PATA_PLATFORM driver
Add HAVE_PATA_PLATFORM to select the pata platform driver
to ensure that we do not end up with a long 'depends on' list
when other users of this driver turn up.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-18 20:28:00 -04:00
Mark Lord
c6112bd86b sata_mv: warn on PIO with multiple DRQs
Chip errata sometimes prevents reliable use of PIO commands which involve
more than a single DRQ (data request).  In normal operation, libata should
not generate such PIO commands (uses DMA instead), but they could be sent
in via SG_IO from userspace.

A full workaround might be to break up such commands into sequences
of single DRQ ones, but that's just way too complex for something
that doesn't normally happen in real life.

So, allow the attempt (it often works, despite the errata),
but log the event for reference when somebody screams.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-18 20:27:58 -04:00
Mark Lord
3bd0a70ee9 sata_mv: enable async_notify for 60x1 Rev.C0 and higher
The early chipsets cannot safely handle Async Notification (AN),
but 6041/6081 chip revision "C0" (and newer) can handle it.

So allow AN for "C0" and higher.

This enables use of hotplug on PMP ports for the 6041/6081 PCI Rev.9 chips.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-18 20:27:55 -04:00
Tejun Heo
5895ef9a5b libata: don't check whether to use DMA or not for no data commands
There's no reason to check whether to use DMA or not for no data
commands.  Don't do it.  While at it, make local variable using_pio in
atapi_xlat() set iff ATAPI_PROT_PIO is going to be used and rename
ata_check_atapi_dma() to atapi_check_dma() for consistency.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-18 20:27:49 -04:00
Tejun Heo
d799e083a8 ahci: jmb361 has only one port
JMB361 has only one port but reports it has two causing longish probe
failure on the second one.  Quirk it.

Reported by Gajo Petrovic in bz 10911.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Gajo Petrovic <gajo01@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2008-06-18 20:27:45 -04:00
Joe Perches
c725801292 drivers/char/agp - use bool
Use boolean in AGP instead of having own TRUE/FALSE

--
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 10:04:20 +10:00
Jan Beulich
da503fa60b agp: two-stage page destruction issue
besides it apparently being useful only in 2.6.24 (the changes in 2.6.25
really mean that it could be converted back to a single-stage mechanism),
I'm seeing an issue in Xen Dom0 kernels, which is caused by the calling
of gart_to_virt() in the second stage invocations of the destroy function.
I think that besides this being a real issue with Xen (where
unmap_page_from_agp() is not just a page table attribute change), this
also is invalid from a theoretical perspective: One should not assume that
gart_to_virt() is still valid after unmapping a page. So minimally (keeping
the 2-stage mechanism) a patch like the one below would be needed.

Jan

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 09:56:16 +10:00
Greg KH
dcd981a77b agp/via: fixup pci ids
add a new PCI ID and remove an old dodgy one, include the explaination
in the commented code so nobody readds later.

(davej also sent the pci id addition).

Signed-off-by: Dave Airlie <airlied@redhat.com>
2008-06-19 09:52:26 +10:00
Linus Torvalds
f9d1c6ca2b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB/uverbs: Fix check of is_closed flag check in ib_uverbs_async_handler()
  RDMA/nes: Fix off-by-one in nes_reg_user_mr() error path
2008-06-18 16:08:59 -07:00
Johannes Berg
ef3a62d272 mac80211: detect driver tx bugs
When a driver rejects a frame in it's ->tx() callback, it must also
stop queues, otherwise mac80211 can go into a loop here. Detect this
situation and abort the loop after five retries, warning about the
driver bug.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-18 15:39:48 -07:00
Jack Morgenstein
fb77bcef9f IB/uverbs: Fix check of is_closed flag check in ib_uverbs_async_handler()
Commit 1ae5c187 ("IB/uverbs: Don't store struct file * for event
files") changed the way that closed files are handled in the uverbs
code.  However, after the conversion, is_closed flag is checked
incorrectly in ib_uverbs_async_handler().  As a result, no async
events are ever passed to applications.

Found by: Ronni Zimmerman <ronniz@mellanox.co.il>

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2008-06-18 15:36:38 -07:00
Stefan Richter
9499fe2b34 ieee1394: Kconfig menu touch-up
Rename and reorder some prompts and modify some help texts.
The result:

  -------------------- IEEE 1394 (FireWire) support --------------------
  *** Enable only one of the two stacks, unless you know what you are doing ***
  New FireWire stack, EXPERIMENTAL
    OHCI-1394 controllers
    Storage devices (SBP-2 protocol)
  Stable FireWire stack
    OHCI-1394 controllers
    PCILynx controller
    Storage devices (SBP-2 protocol)
      Enable replacement for physical DMA in SBP2
    IP over 1394
    raw1394 userspace interface
    video1394 userspace interface
    dv1394 userspace interface (deprecated)
    Excessive debugging output

The old prompts for reference:

  -------------------- IEEE 1394 (FireWire) support --------------------
  IEEE 1394 (FireWire) support - alternative stack, EXPERIMENTAL
    Support for OHCI FireWire host controllers
    Support for storage devices (SBP-2 protocol driver)
  IEEE 1394 (FireWire) support
    *** Subsystem Options ***
    Excessive debugging output
    *** Controllers ***
    Texas Instruments PCILynx support
    OHCI-1394 support
    *** Protocols ***
    OHCI-1394 Video support
    SBP-2 support (Harddisks etc.)
      Enable replacement for physical DMA in SBP2
    IP over 1394
    OHCI-DV I/O support (deprecated)
    Raw IEEE1394 I/O support

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-06-19 00:12:36 +02:00
Stefan Richter
a7b64b8704 firewire: Kconfig menu touch-up
Emphasize the recommendation to build only one stack.
Trim the prompts to better fit into short attention spans.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-06-19 00:12:35 +02:00
Stefan Richter
ae1e535579 firewire: deadline for PHY config transmission
If the low-level driver failed to initialize a card properly without
noticing it, fw-core was blocked indefinitely when trying to send a
PHY config packet.  This hung up the events kernel thread, e.g. locked
up keyboard input.
https://bugzilla.redhat.com/show_bug.cgi?id=444694
https://bugzilla.redhat.com/show_bug.cgi?id=446763

This problem was introduced between 2.6.25 and 2.6.26-rc1 by commit
2a0a259049 "firewire: wait until PHY
configuration packet was transmitted (fix bus reset loop)".

The solution is to wait with timeout.  I tested it with 7 different
working controllers and 1 non-working controller.  On the working ones,
the packet callback complete()s usually --- but not always --- before a
timeout of 10ms.  Hence I chose a safer timeout of 100ms.

On the few tests with the non-working controller ALi M5271, PHY config
packet transmission always timed out so far.  (Fw-ohci needs to be fixed
for this controller independently of this deadline fix.  Often the core
doesn't even attempt to send a phy config because not even self ID
reception works.)

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-06-19 00:12:35 +02:00
Stefan Richter
161b96e782 firewire: fw-ohci: unify printk prefixes
The messages which can be enabled by fw-ohci's debug module parameter
are changed from KERN_DEBUG to KERN_NOTICE level and uniformly prefixed
with "firewire_ohci: ".  This further simplifies communication with
users when we ask them to capture debug messages.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-06-19 00:12:35 +02:00
Stefan Richter
5cb84067d6 firewire: fill_bus_reset_event needs lock protection
Callers of fill_bus_reset_event() have to take card->lock.  Otherwise
access to node data may oops if node removal is in progress.

A lockless alternative would be

-	event->local_node_id = card->local_node->node_id;
+	tmp = fw_node_get(card->local_node);
+	event->local_node_id = tmp->node_id;
+	fw_node_put(tmp);

and ditto with the other node pointers which fill_bus_reset_event()
accesses.  But I went the locked route because one of the two callers
already holds the lock.  As a bonus, we don't need the memory barrier
anymore because device->generation and device->node_id are written in
a card->lock protected section.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
2008-06-19 00:12:35 +02:00
Stefan Richter
affc9c24ad firewire: fw-ohci: write selfIDBufferPtr before LinkControl.rcvSelfID
OHCI 1.1 clause 5.10 requires that selfIDBufferPtr is valid when a 1 is
written into LinkControl.rcvSelfID.

This driver bug has so far not been known to cause harm because most
chips obviously accept a later selfIDBufferPtr write, at least before
HCControl.linkEnable is written.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
2008-06-19 00:12:35 +02:00
Stefan Richter
e896ec4302 firewire: fw-ohci: disable PHY packet reception into AR context
We want the rcvPhyPkt bit in LinkControl off before we start using the
chip.  However, the spec says that the reset value of it is undefined.
Hence switch it explicitly off.

https://bugzilla.redhat.com/show_bug.cgi?id=244576#c48 shows that for
example the nForce2 integrated FireWire controller seems to have it on
by default.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
2008-06-19 00:12:34 +02:00
Stefan Richter
ccff962943 firewire: fw-ohci: use of uninitialized data in AR handler
header_length and payload_length are filled with random data if an
unknown tcode was read from the AR buffer (i.e. if the AR buffer
contained invalid data).

We still need a better strategy to recover from this, but at least
handle_ar_packet now doesn't return out of bound buffer addresses
anymore.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-06-19 00:12:34 +02:00
Stefan Richter
0bf607c5b4 firewire: don't panic on invalid AR request buffer
BUG() at this place is wrong.  (Unless if the low level driver would
already do higher-level input validation of incoming request headers.)

Invalid incoming requests or bugs in the controller which corrupt the
AR-req buffer needlessly crashed the box because this is run in tasklet
context.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2008-06-19 00:12:34 +02:00
Linus Torvalds
a8051fde6b Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog
* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  Revert "[WATCHDOG] hpwdt: Fix NMI handling."
  [WATCHDOG] hpwdt: Add CFLAGS to get driver working
  Revert "[WATCHDOG] make watchdog/hpwdt.c:asminline_call() static"
2008-06-18 12:55:00 -07:00
Linus Torvalds
5dfd06215b Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] dpt_i2o: Add PROC_IA64 define
  [SCSI] scsi_host regression: fix scsi host leak
  [SCSI] sr: fix corrupt CD data after media change and delay
2008-06-18 11:55:43 -07:00
Linus Torvalds
f32c23f59a Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  [POWERPC] Clear sub-page HPTE present bits when demoting page size
  [POWERPC] 4xx: Clear new TLB cache attribute bits in Data Storage vector
2008-06-18 11:55:19 -07:00
Linus Torvalds
e899536470 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6:
  udf: restore UDFFS_DEBUG to being undefined by default
2008-06-18 11:55:03 -07:00
Linus Torvalds
d83b14c0db Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (43 commits)
  netlink: genl: fix circular locking
  Revert "mac80211: Use skb_header_cloned() on TX path."
  af_unix: fix 'poll for write'/ connected DGRAM sockets
  tun: Proper handling of IPv6 header in tun driver when TUN_NO_PI is set
  atl1: relax eeprom mac address error check
  net/enc28j60: low power mode
  net/enc28j60: section fix
  sky2: 88E8040T pci device id
  netxen: download firmware in pci probe
  netxen: cleanup debug messages
  netxen: remove global physical_port array
  netxen: fix portnum for hp mezz cards
  ibm_newemac: select CRC32 in Kconfig
  xfrm: fix fragmentation for ipv4 xfrm tunnel
  netfilter: nf_conntrack_h323: fix module unload crash
  netfilter: nf_conntrack_h323: fix memory leak in module initialization error path
  netfilter: nf_nat: fix RCU races
  atm: [he] send idle cells instead of unassigned when in SDH mode
  atm: [he] limit queries to the device's register space
  atm: [br2864] fix routed vcmux support
  ...
2008-06-18 11:48:40 -07:00
Wim Van Sebroeck
fdf7be6f13 Revert "[WATCHDOG] hpwdt: Fix NMI handling."
The old setup works better.

Signed-off-by: Thomas Mingarelli <Thomas.Mingarelli@hp.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-06-18 16:22:48 +00:00
Paul Mackerras
65ba6cdc83 [POWERPC] Clear sub-page HPTE present bits when demoting page size
When we demote a slice from 64k to 4k, and we are about to insert an
HPTE for a 4k subpage and we notice that there is an existing 64k
HPTE, we first invalidate that HPTE before inserting the new 4k
subpage HPTE.  Since the bits that encode which hash bucket the old
HPTE was in overlap with the bits that encode which of the 16 subpages
have HPTEs, we need to clear out the subpage HPTE-present bits before
starting to insert HPTEs for the 4k subpages.  If we don't do that, we
can erroneously think that a subpage already has an HPTE when it
doesn't.

That in itself wouldn't be such a problem except that when we go to
update the HPTE that we think is present on machines with a
hypervisor, the hypervisor can tell us that the HPTE we think is there
is actually there even though it isn't, which can lead to a process
getting stuck in a loop, continually faulting.  The reason for the
confusion is that the AVPN (abbreviated virtual page number) we are
looking for in the HPTE for a 4k subpage can actually match the AVPN
in a stale HPTE for another 64k page.  For example, the HPTE for
the 4k subpage at 0x84000f000 will be in the same hash bucket and have
the same AVPN as the HPTE for the 64k page at 0x8400f0000.

This fixes the code to clear out the subpage HPTE-present bits.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-18 21:40:43 +10:00
Josh Boyer
b17879f71c [POWERPC] 4xx: Clear new TLB cache attribute bits in Data Storage vector
A recent commit added support for the new 440x6 and 464 cores that have the
added WL1, IL1I, IL1D, IL2I, and ILD2 bits for the caching attributes in the
TLBs.  The new bits were cleared in the finish_tlb_load function, however a
similar bit of code was missed in the DataStorage interrupt vector.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-18 21:40:43 +10:00
Patrick McHardy
6d1a3fb567 netlink: genl: fix circular locking
genetlink has a circular locking dependency when dumping the registered
families:

- dump start:
genl_rcv()            : take genl_mutex
genl_rcv_msg()        : call netlink_dump_start() while holding genl_mutex
netlink_dump_start(),
netlink_dump()        : take nlk->cb_mutex
ctrl_dumpfamily()     : try to detect this case and not take genl_mutex a
                        second time

- dump continuance:
netlink_rcv()         : call netlink_dump
netlink_dump          : take nlk->cb_mutex
ctrl_dumpfamily()     : take genl_mutex

Register genl_lock as callback mutex with netlink to fix this. This slightly
widens an already existing module unload race, the genl ops used during the
dump might go away when the module is unloaded. Thomas Graf is working on a
seperate fix for this.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-18 02:07:07 -07:00
David S. Miller
3a5be7d4b0 Revert "mac80211: Use skb_header_cloned() on TX path."
This reverts commit 608961a5ec.

The problem is that the mac80211 stack not only needs to be able to
muck with the link-level headers, it also might need to mangle all of
the packet data if doing sw wireless encryption.

This fixes kernel bugzilla #10903.  Thanks to Didier Raboud (for the
bugzilla report), Andrew Prince (for bisecting), Johannes Berg (for
bringing this bisection analysis to my attention), and Ilpo (for
trying to analyze this purely from the TCP side).

In 2.6.27 we can take another stab at this, by using something like
skb_cow_data() when the TX path of mac80211 ends up with a non-NULL
tx->key.  The ESP protocol code in the IPSEC stack can be used as a
model for implementation.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-18 01:19:51 -07:00
Rainer Weikusat
3c73419c09 af_unix: fix 'poll for write'/ connected DGRAM sockets
The unix_dgram_sendmsg routine implements a (somewhat crude)
form of receiver-imposed flow control by comparing the length of the
receive queue of the 'peer socket' with the max_ack_backlog value
stored in the corresponding sock structure, either blocking
the thread which caused the send-routine to be called or returning
EAGAIN. This routine is used by both SOCK_DGRAM and SOCK_SEQPACKET
sockets. The poll-implementation for these socket types is
datagram_poll from core/datagram.c. A socket is deemed to be writeable
by this routine when the memory presently consumed by datagrams
owned by it is less than the configured socket send buffer size. This
is always wrong for connected PF_UNIX non-stream sockets when the
abovementioned receive queue is currently considered to be full.
'poll' will then return, indicating that the socket is writeable, but
a subsequent write result in EAGAIN, effectively causing an
(usual) application to 'poll for writeability by repeated send request
with O_NONBLOCK set' until it has consumed its time quantum.

The change below uses a suitably modified variant of the datagram_poll
routines for both type of PF_UNIX sockets, which tests if the
recv-queue of the peer a socket is connected to is presently
considered to be 'full' as part of the 'is this socket
writeable'-checking code. The socket being polled is additionally
put onto the peer_wait wait queue associated with its peer, because the
unix_dgram_sendmsg routine does a wake up on this queue after a
datagram was received and the 'other wakeup call' is done implicitly
as part of skb destruction, meaning, a process blocked in poll
because of a full peer receive queue could otherwise sleep forever
if no datagram owned by its socket was already sitting on this queue.
Among this change is a small (inline) helper routine named
'unix_recvq_full', which consolidates the actual testing code (in three
different places) into a single location.

Signed-off-by: Rainer Weikusat <rweikusat@mssgmbh.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-17 22:28:05 -07:00