Commit Graph

58152 Commits

Author SHA1 Message Date
John Daiker
05c9a4cfe4 airo_cs: checkpatch.pl cleanups
Hopefully nothing controversial here, since the driver hasn't been touched in a while!

Before: 36 errors, 6 warnings, 482 lines checked
After:  0 errors, 3 warnings, 485 lines checked

This was nearly all trailing whitespace, * and parenthesis spacing, and code indent changes.

md5sum of object file before and after are identical.

Signed-off-by: John Daiker <daikerjohn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:35 -04:00
Vasanthakumar Thiagarajan
be1b08af61 ath9k: Use suitable macros with 4k eeprom data
This patch improves range and connection stability in AR9285.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:34 -04:00
Helmut Schaa
cc88aff073 ipw2x00: remove obsolete enums
Remove obsolete enums from ipw2x00/ieee80211.h, they are not used anymore.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:34 -04:00
Helmut Schaa
d74cc9a7a3 ipw2x00: Use IE definitions from linux/ieee80211.h
Use IE definitions from linux/ieee80211.h and drop the appropriate enum
from ipw2x00/ieee80211.h

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:34 -04:00
Helmut Schaa
30e1863ccb ipw2x00: remove duplicated defines
Remove several duplicated defines from ipw2x00/ieee80211.h which are
also available in linux/ieee80211.h.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:33 -04:00
Helmut Schaa
3756162b06 libipw: fix debug output
Replace all remaining occurrences of CONFIG_IEEE80211_DEBUG with
CONFIG_LIBIPW_DEBUG in libipw to allow debug output again.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:33 -04:00
Gabor Juhos
5077fd358b ath9k: always compile ath_radio_{en,dis}able
ath_radio_{en,dis}able is only compiled if RFKILL is enabled, but it is
required by the 'ath9k_wiphy_select' function.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:33 -04:00
Gabor Juhos
5210311543 ath9k: fix compile error in debug.c
drivers/net/wireless/ath9k/debug.c: In function 'read_file_wiphy':
drivers/net/wireless/ath9k/debug.c:377: error: implicit declaration of
function 'put_unaligned_le32'
drivers/net/wireless/ath9k/debug.c:378: error: implicit declaration of
function 'put_unaligned_le16'

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:32 -04:00
Gabor Juhos
9251f0b418 ath9k: fix compile error in ahb.c
drivers/net/wireless/ath9k/ahb.c: In function 'ath_ahb_probe':
drivers/net/wireless/ath9k/ahb.c:136: error: 'aphy' undeclared (first
use in this function)

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:32 -04:00
Gabor Juhos
6b765deb01 ath9k: fix AR_SREV_9100_OR_LATER macro
The current macro is wrong, because detects some AR5416 devices as an
AR9100 device. The AR5416 devices would have performance issues after
this change, because the contents of the ar5416 specific and of the
ar9100 specificinitval arrays are swapped. Fortunately we can correct
this with the rename of the arrays simply.

Changes-licesed-under: ISC

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:32 -04:00
Gabor Juhos
d4376ebe16 ath9k: move ar9100 version checking macros into a more appropriate place
All other version checking macros are in a common location within the
reg.h file. The AR_SREV_9100_OR_LATER macro is wrong currently, but will
be fixed with the next patch.

Changes-licensed-under: ISC

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:32 -04:00
Gabor Juhos
a8c96d3b22 ath9k: cleanup AR5416 version checking macros
Currently we have two different versions of this macros. Because they
would have to do the same thing, we should simplify and merge them.

Changes-licensed-under: ISC

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:31 -04:00
Senthil Balasubramanian
978b532642 ath9k: Incorrect AR9285 version check macro
Fix AR9285 1.1 and 1.2 version check macro.

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:31 -04:00
Senthil Balasubramanian
4e84516838 ath9k: INI update for AR9285 and periodic PA offset caliberation
This patch updates the initvalues for AR9285 chipset and also adds
periodic PA offset caliberation.

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:31 -04:00
Senthil Balasubramanian
b03a9db95a ath9k: RX buffers may be accessed/freed even before initialized/alloced.
accessing RXBUF list in ath_rx_cleanup may cause panic if
ath_descdma_setup fails even before RXBUF list is initialized.

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:30 -04:00
Senthil Balasubramanian
f0e6ce13c1 ath9k: Get rid of unnecessary ATOMIC memory alloc during init time
We can sleep for memory during init time and so allocating rx buffers,
descriptro buffers with GFP_KERNEL should help us to get rid of transient
alloc fails.

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:30 -04:00
Luis R. Rodriguez
22cad73587 mac80211_hwsim: add support for 5 GHz
ACME Inc. is now selling a dual band radio.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:29 -04:00
Christian Lamparter
94041b2940 p54: enable power save support
This patch enables power save support on all p54 devices.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:28 -04:00
Christian Lamparter
d0b45aef4f p54: initial SoftLED support
This patch adds SoftLED support for all p54 devices.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:28 -04:00
Christian Lamparter
efeada2c0a p54: fix iwconfig txpower off
Disabling the receiver logic with P54_FILTER_TYPE_RX_DISABLED is not
supported by all firmwares. However we have an alternative: hibernation.
And the only side effect - so far - is a bit less power consumption. WIN!

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:28 -04:00
Christian Lamparter
ad5e72ee81 p54pci: convert printk(KERN_* to dev_*
This patch replaces most printk(KERN_* "") with their by dev_* analogue.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:28 -04:00
Christian Lamparter
2ac710720c p54: unify ieee80211 device registration
All three drivers (p54pci, p54usb and p54spi) are implementing the
same functionality three times. So, why not put it into the shared library?!

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:27 -04:00
Christian Lamparter
fbf95296c1 p54usb: stop USB core interference in exit path
The patch fixes a problem when the (Soft)LED stayed on after the module was unloaded.
It turned out that the USB core disables all endpoints before calling the disconnect method.
So it was impossible to switch off the radio & LEDs.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:27 -04:00
Gabor Juhos
19d8bc22bc ath9k: create a common debugfs_root for all device instances
The driver are trying to create an 'ath9k' directory in debugfs for each
device currently. If there are more than one device in the system, the
second try will always fail.

Changes-licensed-under: ISC

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:27 -04:00
Andrey Borzenkov
2bfc5cb57b orinoco: firmware: consistently compile out fw cache support if not requested
Currently part of support for FW caching is unconditionally compiled
in even if it is never used. Consistently remove caching support if
not requested by user.

Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-03-16 18:09:26 -04:00
Dhananjay Phadke
ff4fbd43fe netxen: update version to 4.0.30
To mark all features and bugfixes submitted since 4.0.11.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 14:00:34 -07:00
Dhananjay Phadke
d8b100c5da netxen: add receive side scaling (rss) support
This patch enables the load balancing capability of firmware
and hardware to spray traffic into different cpus through
separate rx msix interrupts.

The feature is being enabled for NX3031, NX2031 (old) will be
enabled later. This depends on msi-x and compatibility with
msi and legacy is maintained by enabling single rx ring.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 14:00:33 -07:00
Dhananjay Phadke
9b3ef55c6d netxen: remove old lro code
Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 14:00:33 -07:00
Dhananjay Phadke
438627c77b netxen: sanitize variable names
o remove max_ prefix from ring sizes, since they don't really
  represent max possible sizes.
o cleanup naming of rx ring types (normal, jumbo, lro).
o simplify logic to choose rx ring size, gig ports get half
  rx ring of 10 gig ports.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 14:00:32 -07:00
Dhananjay Phadke
0b72e659a1 netxen: add suspend resume support
Detach network interface on PCI suspend and recreate hardware
context after resumes.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 14:00:31 -07:00
Dhananjay Phadke
fbb52f2272 netxen: fix endianness in serial number
Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 14:00:31 -07:00
Jesse Brandeburg
4df1046622 ixgbe: Cleanup some whitespace issues, fixup and add some comments
Cleanup a bit of whitespace, add some function header comments, and fix a
few comments around the driver.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Acked-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:13 -07:00
PJ Waskiewicz
885125399e ixgbe: Two small fixes for 82599 when bringing the device down and for WoL
The Tx DMA unit should be disabled when bringing the device down.  Also,
the KX4 device with 82599 supports WoL, so we should clear the Wake Up
Status (WUS) after a PCIe slot reset.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:13 -07:00
Jesse Brandeburg
9891ca7cdc ixgbe: Add a few safety nets for register writes and descriptor cleanups
There are possible times that a driver may fail to completely initialize,
due to a buggy platform or a buggy kernel.  In those cases, we'd rather
fail gracefully instead of a panic.  Add a few safety checks to some
critical paths to try and prevent a panic in these corner-case situations.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:12 -07:00
Jesse Brandeburg
2a41ff8116 ixgbe: Cleanup on the Rx init path
This cleans up the following pieces of the Rx initialization path:

- Enable the ECC memory fault interrupt in OTHER causes.

- Fix an 82598 initialization of RDRXCTL when depending on RSS and VMDq to
be enabled.  We don't need these features enabled to safely set the MVMEN
bit to allow multiple SRRCTL register mappings into the RXDCTL registers.

- Fix the RSS initialization path to not stomp on DCB accidentally.  When
configuring the MRQC (multiple Rx queue contol) register, we want to make
sure we only OR in features as necessary, instead of full assignment.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:11 -07:00
Jesse Brandeburg
9a1a69adad ixgbe: Fix the Tx clean logic to return proper status
The Tx accounting when cleaning during NAPI was not completely properly.
We should use the work_limit to determine when to finish cleaning, and
use the same to return the cleaned status.  The impact of running like this
causes the NAPI clean for this Tx to get stuck in a scheduling loop, and
can result in Tx not getting cleaned, ending with a Tx hang and device
reset.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:11 -07:00
Jesse Brandeburg
4dd64df895 ixgbe: fix bug with napi add before request_irq
Occasionally if the driver was loaded in a system that
didn't support MSI-X or MSI and was on a shared interrupt,
the driver would then panic in NAPI on the first shared
interrupt because we hadn't called napi_add yet.

Solution: call napi_add before calling request_irq

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:10 -07:00
Jesse Brandeburg
509ee935ec ixgbe: Fix interrupt configuration for 82599
The interrupt models using EITR have changed in 82599.  The way the register
is laid out, the change is transparent to some of the existing code.
However, some of it isn't.  This patch fixes all the cases where EITR
handling is different than 82598.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:08 -07:00
PJ Waskiewicz
40dcd79a7b ixgbe: Disable DROP_EN for Rx queues
82599 mistakenly enabled drop on Rx queues in the packet buffer.  The
default mode should be store-and-forward from the FIFO.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Acked-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:07 -07:00
PJ Waskiewicz
d51019a4da ixgbe: Fix an accounting problem when the Rx FIFO is full
The rx_no_dma_resources counter reported by ethtool -S ethX is not
counting correctly.  In 82599, the queue mappings for the counters need
to be mapped properly, and accounted for properly.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Acked-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:07 -07:00
PJ Waskiewicz
1339b9e975 ixgbe: Fix get_supported_physical_layer() due to new 82599 PHY types
A purely cosmetic change.  Report which physical layer is present, instead
of PHY unknown.  82599 added new PHY types for the SFP+ devices, and this
was missed getting updated.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:06 -07:00
Alexander Duyck
c8ea5ea9da igb: add support for 82576 quad copper adapter
Add support for 82576 copper adapter and necessary code to restrict wol for
quad port adapter to first port.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:06 -07:00
Alexander Duyck
9eb2341d0d igb: add support for another dual port 82576 non-security nic
Adding device id to support 82576NS dual port copper
NIC.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:05 -07:00
Alexander Duyck
75f4f382e3 igb: correct typo that was setting vfta mask to 1
This patch corrects a typo that was doing a less than comparison instead of
a left shift due to the fact that I didn't get enough <'s in there.

This resolves an issue in which vlans were not functioning correctly.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:04 -07:00
Alexander Duyck
cad6d05f56 igb: add PF to pool
Add Pf to pool if adding a VLVF register value and the VFTA bit is
already set.

This patch addresses the unlikely situation that the PF adds a vlan
entry when the vlvf is full, and a vf later adds the vlan to the vlvf.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:03 -07:00
Alexander Duyck
a2cf8b6ce1 igb: support wol on second port
We need to support wol on the second port for situations such as when the
lan ports are on the motherboard itself.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:03 -07:00
Alexander Duyck
bd38e5d124 igb: resolve warning of unused adapter struct
If DCA is undefined then the adapter struct becomes unnecessary.  To
resolve this issue the DCA calls can simply make a call to the adapter
struct through the rx_ring adapter struct member.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:02 -07:00
Alexander Duyck
5e6d5b17db igb: remove netif running call from igb_poll
The netif_running check in igb poll is a hold over from the use of fake
netdevs to use multiple queues with NAPI prior to 2.6.24.  It is no longer
necessary to have the call there and it currently can cause errors if
work_done == budget.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:01 -07:00
Maciej Sosnowski
92be791759 igb: switch to new dca API
With the new DCA API, the driver should use dca3_get_tag() instead of
the obsolete dca_get_tag().

Signed-off-by: Maciej Sosnowski < maciej.sosnowski@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-14 12:41:01 -07:00
Gabriele Paoloni
9c705260fe ppp: ppp_mp_explode() redesign
I found the PPP subsystem to not work properly when connecting channels
with different speeds to the same bundle.

Problem Description:

As the "ppp_mp_explode" function fragments the sk_buff buffer evenly
among the PPP channels that are connected to a certain PPP unit to
make up a bundle, if we are transmitting using an upper layer protocol
that requires an Ack before sending the next packet (like TCP/IP for
example), we will have a bandwidth bottleneck on the slowest channel
of the bundle.

Let's clarify by an example. Let's consider a scenario where we have
two PPP links making up a bundle: a slow link (10KB/sec) and a fast
link (1000KB/sec) working at the best (full bandwidth). On the top we
have a TCP/IP stack sending a 1000 Bytes sk_buff buffer down to the
PPP subsystem. The "ppp_mp_explode" function will divide the buffer in
two fragments of 500B each (we are neglecting all the headers, crc,
flags etc?.). Before the TCP/IP stack sends out the next buffer, it
will have to wait for the ACK response from the remote peer, so it
will have to wait for both fragments to have been sent over the two
PPP links, received by the remote peer and reconstructed. The
resulting behaviour is that, rather than having a bundle working
@1010KB/sec (the sum of the channels bandwidths), we'll have a bundle
working @20KB/sec (the double of the slowest channels bandwidth).


Problem Solution:

The problem has been solved by redesigning the "ppp_mp_explode"
function in such a way to make it split the sk_buff buffer according
to the speeds of the underlying PPP channels (the speeds of the serial
interfaces respectively attached to the PPP channels). Referring to
the above example, the redesigned "ppp_mp_explode" function will now
divide the 1000 Bytes buffer into two fragments whose sizes are set
according to the speeds of the channels where they are going to be
sent on (e.g .  10 Byets on 10KB/sec channel and 990 Bytes on
1000KB/sec channel).  The reworked function grants the same
performances of the original one in optimal working conditions (i.e. a
bundle made up of PPP links all working at the same speed), while
greatly improving performances on the bundles made up of channels
working at different speeds.

Signed-off-by: Gabriele Paoloni <gabriele.paoloni@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-13 16:09:12 -07:00