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path: root/drivers/net
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2010-08-05libertas: get the right # of scanned BSSesDan Williams
Let's actually check the right field in the command response; and if there aren't any reported BSSes, exit early with success. Signed-off-by: Dan Williams <dcbw@redhat.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04iwlagn: Improve aggregation failure error messagesAndy Lutomirski
82ca9341763107615a15da6e59b9535d49eb91c3 added scary looking but harmless error messages. Make them clearer and make the actual failure message show up with the same severity as the harmless one. Signed-off-by: Andy Lutomirski <luto@mit.edu> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04rt2x00: do not use PCI resources before pci_enable_device()Kulikov Vasiliy
IRQ and resource[] may not have correct values until after PCI hotplug setup occurs at pci_enable_device() time. The semantic match that finds this problem is as follows: // <smpl> @@ identifier x; identifier request ~= "pci_request.*|pci_resource.*"; @@ ( * x->irq | * x->resource | * request(x, ...) ) ... *pci_enable_device(x) // </smpl> Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Acked-by: Gertjan van Wingerde <gwingerde@gmail.com> Acked-by: Ivo van Doorn <IvDoorn@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04wireless: ipw2100: check result of kzalloc()Christoph Fritz
If kzalloc() fails return with -ENOMEM from ipw2100_net_init() which is called by register_netdev. CC: Dan Carpenter <error27@gmail.com> Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k: fix erased ieee80211_rx_status.mactimeJan Friedrich
ath9k_rx_skb_preprocess nulls rxs and the mactime is never set again - mactime is always 0. This causes problems in IBSS mode. ieee80211_rx_bss_info uses mactime to decide if an IBSS merge is needed. Without this patch the merge is triggered by each beacon received. This can be recognized by the "beacon TSF higher than local TSF - IBSS merge with BSSID" log message accompanying each beacon. This problem was not completely fixed in commit a6d2055b02dde1067075795274672720baadd3ca and is not a stable kernel fix. It is solely intended for wireless-testing. Signed-off-by: Jan Friedrich <jft@dev2day.de> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04p54pci: Add PCI ID for SMC2802WLarry Finger
The SMC2802W appears to work with p54pci. Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Tested-by: David Cozatt <olbrannon@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k: fix an issue in ath_atx_tid paused flag managementLorenzo Bianconi
I noticed a possible issue in the paused flag management of the ath_atx_tid data structure. In particular, in a noisy environment and under heavy load, I observed that the AGGR session establishment could fail several times consecutively causing values of the paused flag greater than one for this TID (ath_tx_pause_tid is called more than once from ath_tx_aggr_start). Considering that the session for this TID can not be established also after the mac80211 stack calls the ieee80211_agg_tx_operational() since the ath_tx_aggr_resume() lowers the paused flag only by one. This patch also replaces some BUG_ON calls with WARN_ON, as even if these unlikely conditions happen, it's not fatal enough to justify a BUG_ON. Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com> Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k_hw: Fix regulatory CTL index usage for AR9003Luis R. Rodriguez
AR9003 was not relying on the CTL indexes from the EEPROM for capping the max output power. The CTL indexes from the EEPROM provide calibrated limits for output power for each tested and supported frequency. Without this the device operates at a power level which only conforms to the transmit spectrum mask as specified by IEEE Annex I.2.3. The regulatory limit by CRDA is always used but does not provide calibrated values for optimal performance, specially on band edges. Using the calibrated data from the EEPROM ensures the device operates at optimal output power while still ensuring proper regulatory compliance. The device uses the minimum of these tree values, the value from CRDA, the calibrated value from CTL indexex, and the value to conform to the IEEE transmit spectrum mask. Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04net: wl12xx: do not use kfree'd memoryKulikov Vasiliy
wl1271_dump() uses cmd after kfree(cmd). Move kfree() just after wl1271_dump(). Signed-off-by: Kulikov Vasiliy <segooon@gmail.com> Acked-by: Juuso Oikarinen <juuso.oikarinen@nokia.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04iwlagn: fix typo in ucode_bt_stats_read debugfsWey-Yi Guy
small typo fix in ucode_bt_stats_read debugfs file Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04iwlwifi: BA scd_flow not match condition detectedWey-Yi Guy
It is a uCode bug which cause the tx queue id not match scd_flow in compressed block ack frame, and it need to be addressed in uCode. Currently, driver will log the information when it happen. Since it is possible happen very often and we do not want to fill the syslog, so don't enable the logging by default. Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04iwlwifi: fix compile warningJohannes Berg
When iwlwifi is compiled w/o debug, we get this warning: iwl-agn.c: In function ‘iwlagn_load_firmware’: iwl-agn.c:2014: warning: passing argument 3 of ‘iwl_print_hex_dump’ discards qualifiers from pointer target type iwl-debug.h:73: note: expected ‘void *’ but argument is of type ‘const u8 *’ because the const qualifier is missing in the inline stub. Fix this. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k_hw: fix a noise floor calibration related race conditionFelix Fietkau
On AR5008-AR9002, other forms of calibration must not be started while the noise floor calibration is running, as this can create invalid readings which were sometimes not even recoverable by any further calibration attempts. This patch also ensures that the result of noise floor measurements are processed faster and also allows the result of the initial calibration on reset to make it into the NF history buffer Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k_hw: clean up per-channel calibration dataFelix Fietkau
The noise floor history buffer is currently not kept per channel, which can lead to problems when changing channels from a clean channel to a noisy one. Also when switching from HT20 to HT40, the noise floor history buffer is full of measurements, but none of them contain data for the extension channel, which it needs quite a bit of time to recover from. This patch puts all the per-channel calibration data into a single data structure, and gives the the driver control over whether that is used per-channel or even not used for some channels. For ath9k_htc, I decided to keep this per-channel in order to avoid creating regressions. For ath9k, the data is kept only for the operating channel, which saves some space. ath9k_hw takes care of wiping old data when the operating channel or its channel flags change. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k: prevent calibration during off-channel activityFelix Fietkau
Previously the software scan callback was used to indicate to the hardware, when it was safe to calibrate. This didn't really work properly, because it depends on a specific order of software scan callbacks vs. channel changes. Also, software scans are not the only thing that triggers off-channel activity, so it's better to use the newly added indication from mac80211 for this and not use the software scan callback for anything calibration related. This fixes at least some of the invalid noise floor readings that I've seen in AP mode on AR9160 Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k_hw: fix analog shift register writes on AR9003Felix Fietkau
Writes to the analog shift registers, which are issues by the initval programming function, require a 100 usec delay (similar to AR9002, but in a different register range). Signed-off-by: Felix Fietkau <nbd@openwrt.org> Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k: fix a crash in the PA predistortion apply functionFelix Fietkau
When updating the PAPRD table in hardware, PAPRD itself needs to be disabled first, otherwise the hardware can throw a data bus error, which upsets at least some platforms. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k_hw: fix periodic noise floor calibration on AR9003Felix Fietkau
The periodic noise floor calibration is broken on this chip family, because it keeps triggering a software-filtered noise floor calibration, but never reads the result before uploading the history buffer value to the hardware. Fix this with a call to ath9k_hw_getnf(), just like on AR9002. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04ath9k_hw: clean up and fix initial noise floor calibrationFelix Fietkau
On AR9003 the initial noise floor calibration is currently triggered at the end of the reset without allowing the hardware to update the baseband settings. This could potentially make scans in noisy environments a bit more unreliable, so use the same calibration sequence that is used on AR9002. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-04iwlwifi: fix possible recursive locking deadlockJohannes Berg
commit f84b29ec0a1ab767679d3f2428877b65f94bc3ff Author: Johannes Berg <johannes.berg@intel.com> Date: Tue May 18 02:29:13 2010 -0700 iwlwifi: queue user-initiated scan when doing internal scan introduced a potential deadlock because it calls ieee80211_scan_completed() with the priv->mutex held, but mac80211 may call back into iwlwifi which would lead to recursive locking. Move this out from under the mutex. Cc: stable@kernel.org Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-08-03phy/marvell: add 88ec048 supportCyril Chemparathy
Marvell 88ec048 is a derivative of its 88e1121r device. From the programmer's perspective, the one major difference is the addition of an additional control bit in Page 2 Register 16 - used to control the padding of odd nibble preambles. This patch adds support for this new device, while inheriting as much code as possible from the existing 88e1121r implementation. Signed-off-by: Cyril Chemparathy <cyril@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-03igb: Program MDICNFG register prior to PHY initAlexander Duyck
This patch addresses an issue seen on 82580 in which the MDICNFG register will be reset during a single function reset and as a result we will be unable to communicate with the PHY. To correct the issue, added a call to reset_mdicnfg just prior to the first access of the MDICNFG register in sgnii_uses_mdio. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-03e1000e: correct MAC-PHY interconnect register offset for 82579Bruce Allan
The MAC-PHY interconnect register set on ICH/PCH parts is accessed through a peephole mechanism by writing an offset to a CSR register. The offset for the interconnect's half-duplex control register (which is used in a jumbo frame workaround for 82579) is incorrect. Signed-off-by: Bruce Allan <bruce.w.allan@intel.com> Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-03hso: Add new product IDFilip Aben
This patch adds a new product ID to the hso driver. Signed-off-by: Filip Aben <f.aben@option.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-03can: Add driver for esd CAN-USB/2 deviceMatthias Fuchs
This patch adds a driver for esd's USB high speed CAN interface. The driver supports devices with multiple CAN interfaces. Signed-off-by: Matthias Fuchs <matthias.fuchs@esd.eu> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/e1000e/hw.h net/bridge/br_device.c net/bridge/br_input.c
2010-08-02phy/marvell: add 88e1121 interface mode supportCyril Chemparathy
This patch adds support for RGMII RX/TX delay configuration on marvell 88e1121 and derivatives. With this patch, PHY_INTERFACE_MODE_RGMII_*ID modes are now supported on these devices. Signed-off-by: Cyril Chemparathy <cyril@ti.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02net: Fix a typo from "dev" to "ndev"Henrique Camargo
The typo was causing compilation errors since "dev" was not defined. Signed-off-by: Henrique Camargo <henrique.camargo@ensitec.com.br> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02igb: Use irq_synchronize per vector when using MSI-XEmil Tantilov
Synchronize all IRQs when using MSI-X. Similar to ixgbe. Issue was reported on e1000e, but the patch is also valid for igb. CC: Jean Delvare <jdelvare@suse.de> Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com> Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02ixgbevf: fix null pointer dereference due to filter being set for VLAN 0Alexander Duyck
This change corrects an issue that resulted in a null pointer dereference for the addition of VLAN 0 without any VLANs being registered. Also this code removes some unnecessary checks for defines and the unnecessary setting of VLAN flags since that is now handled within the kernel via the vlan_features. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Tested-by: Emil Tantilov <emil.s.tantilov@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02e1000e: Fix irq_synchronize in MSI-X caseJeff Kirsher
Based on original patch/work from Jean Delvare <jdelvare@suse.de> Synchronize all IRQs when in MSI-X IRQ mode. Jean's original patch hard coded the sync with the 3 possible vectors, this patch incorporates more flexibility for the future and aligns with how igb stores the number of vectors into the adapter structure. CC: Jean Delvare <jdelvare@suse.de> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com> Acked-by: Bruce Allan <bruce.w.allan@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02e1000e: register pm_qos request on hardware activationFlorian Mickler
The pm_qos_add_request call has to register the pm_qos request with the pm_qos susbsystem before first use of the pm_qos request via pm_qos_update_request. As pm_qos changed to use plists there is no benefit in registering and unregistering the pm_qos request on ifup/ifdown and thus we move the registering into e1000_open and the unregistering in e1000_close. This fixes the following warning: [ 1.786060] WARNING: at kernel/pm_qos_params.c:264 pm_qos_update_request+0x28/0x54() [ 1.786088] Hardware name: Latitude E6500 [ 1.787045] pm_qos_update_request() called for unknown object [ 1.787966] Modules linked in: [ 1.788940] Pid: 1, comm: swapper Not tainted 2.6.35-rc5-mmotm0719 #1 [ 1.790035] Call Trace: [ 1.791121] [<ffffffff81037335>] warn_slowpath_common+0x80/0x98 [ 1.792205] [<ffffffff810373e1>] warn_slowpath_fmt+0x41/0x43 [ 1.793279] [<ffffffff81057c14>] pm_qos_update_request+0x28/0x54 [ 1.794347] [<ffffffff8134889e>] e1000_configure+0x421/0x459 [ 1.795393] [<ffffffff8134afbd>] e1000_open+0xbd/0x37c [ 1.796436] [<ffffffff8105743a>] ? raw_notifier_call_chain+0xf/0x11 [ 1.797491] [<ffffffff8145f948>] __dev_open+0xae/0xe2 [ 1.798547] [<ffffffff8145f997>] dev_open+0x1b/0x49 [ 1.799612] [<ffffffff8146e36e>] netpoll_setup+0x84/0x259 [ 1.800685] [<ffffffff81b5037c>] init_netconsole+0xbc/0x21f [ 1.801744] [<ffffffff81b5026c>] ? sir_wq_init+0x0/0x35 [ 1.802793] [<ffffffff81b502c0>] ? init_netconsole+0x0/0x21f [ 1.803845] [<ffffffff810002ff>] do_one_initcall+0x7a/0x12f [ 1.804885] [<ffffffff81b2ccae>] kernel_init+0x138/0x1c2 [ 1.805915] [<ffffffff81003554>] kernel_thread_helper+0x4/0x10 [ 1.806937] [<ffffffff81590e00>] ? restore_args+0x0/0x30 [ 1.807955] [<ffffffff81b2cb76>] ? kernel_init+0x0/0x1c2 [ 1.808958] [<ffffffff81003550>] ? kernel_thread_helper+0x0/0x10 [ 1.809958] ---[ end trace 84b562a00a60539e ]--- Signed-off-by: Florian Mickler <florian@mickler.org> Tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: update driver versionDimitris Michailidis
Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: add new PCI IDsDimitris Michailidis
Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: fix wrong shift directionDimitris Michailidis
Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: support running the driver on PCI functions besides 0Dimitris Michailidis
Add support for running the driver on any PCI function. Mostly this entails replacing a constant 0 in a number of calls with the variable function number. Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: advertise NETIF_F_TSO_ECNDimitris Michailidis
The device supports TSO+ECN. Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: get on-chip queue info from FW and create a memory window for themDimitris Michailidis
Get info about the availability of Tx on-chip queues from FW and if they are supported set up a memory window for them. iw_cxgb4 will be using them. Move the existing window setup later in the init sequence, after we have collected the new info. Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: fix TSO descriptorsDimitris Michailidis
Commit 1704d74894912b8ecc3e95cecd7bde336a0b1bf2 ("cxgb4vf: small changes to message processing structures/macros") was incomplete and causes cxgb4 to write bad TSO descriptors. Fix that up by reverting the offending part of that commit and adjusting field accesses now that they are one level deeper. Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: don't offload Rx checksums for IPv6 fragmentsDimitris Michailidis
The checksum provided by the device doesn't include the L3 headers, as IPv6 expects. Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02cxgb4: disable an interrupt that is neither used nor servicedDimitris Michailidis
Signed-off-by: Dimitris Michailidis <dm@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02hp100: unmap memory on error pathDan Carpenter
There was an error path where "mem_ptr_virt" didn't get unmapped. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02Tulip: don't initialize SBE xT3E3 WAN ports.Krzysztof Hałasa
SBE 2T3E3 cards use DECchips 21143 but they need a different driver. Don't even try to use a normal tulip driver with them. Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02drivers/net/wan/farsync.c: Use standard pr_<level>Joe Perches
Remove locally defined equivalents Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02tg3: Update version to 3.113Matt Carlson
This patch updates the tg3 version to 3.113. Reviewed-by: Benjamin Li <benli@broadcom.com> Reviewed-by: Michael Chan <mchan@broadcom.com> Signed-off-by: Matt Carlson <mcarlson@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02tg3: Migrate tg3_flags to phy_flagsMatt Carlson
This patch moves most of the phy related flag definitions over to the phyflags member and changes the code accordingly. Reviewed-by: Benjamin Li <benli@broadcom.com> Reviewed-by: Michael Chan <mchan@broadcom.com> Signed-off-by: Matt Carlson <mcarlson@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02tg3: Create phy_flags and migrate phy_is_low_powerMatt Carlson
This patch deletes the link_config.phy_is_low_power flag and creates a new phy_flags device member to store all phy related settings. All the code is converted accordingly. Reviewed-by: Benjamin Li <benli@broadcom.com> Reviewed-by: Michael Chan <mchan@broadcom.com> Signed-off-by: Matt Carlson <mcarlson@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02tg3: Add phy-related preprocessor constantsMatt Carlson
This patch replaces some instances of hardcoded phy register values with preprocessor equivalents. Reviewed-by: Benjamin Li <benli@broadcom.com> Reviewed-by: Michael Chan <mchan@broadcom.com> Signed-off-by: Matt Carlson <mcarlson@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02tg3: Add error reporting to tg3_phydsp_write()Matt Carlson
This patch adds error reporting to the tg3_phydsp_write() function and converts a few more locations to use this function over the inlined equivalent. Reviewed-by: Benjamin Li <benli@broadcom.com> Reviewed-by: Michael Chan <mchan@broadcom.com> Signed-off-by: Matt Carlson <mcarlson@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-02tg3: Improve small packet performanceMatt Carlson
smp_mb() inside tg3_tx_avail() is used twice in the normal tg3_start_xmit() path (see illustration below). The full memory barrier is only necessary during race conditions with tx completion. We can speed up the tx path by replacing smp_mb() in tg3_tx_avail() with a compiler barrier. The compiler barrier is to force the compiler to fetch the tx_prod and tx_cons from memory. In the race condition between tg3_start_xmit() and tg3_tx(), we have the following situation: tg3_start_xmit() tg3_tx() if (!tg3_tx_avail()) BUG(); ... if (!tg3_tx_avail()) netif_tx_stop_queue(); update_tx_index(); smp_mb(); smp_mb(); if (tg3_tx_avail()) if (netif_tx_queue_stopped() && netif_tx_wake_queue(); tg3_tx_avail()) With smp_mb() removed from tg3_tx_avail(), we need to add smp_mb() to tg3_start_xmit() as shown above to properly order netif_tx_stop_queue() and tg3_tx_avail() to check the ring index. If it is not strictly ordered, the tx queue can be stopped forever. This improves performance by about 3% with 2 ports running bi-directional 64-byte packets. Reviewed-by: Benjamin Li <benli@broadcom.com> Signed-off-by: Michael Chan <mchan@broadcom.com> Signed-off-by: Matt Carlson <mcarlson@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>