If slave sysfs symlink failes to be created - we end up without removing
the master sysfs symlink. Remove it in case of failure.
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jeff Kirsher says:
====================
This series contains updates to ixgbevf and igb.
The ixgbevf calls to pci_disable_msix() and to free the msix_entries
memory should not occur if device open fails. Instead they should be
called during device driver removal to balance with the call to
pci_enable_msix() and the call to allocate msix_entries memory
during the device probe and driver load.
The remaining 4 of 5 igb patches are simple 1-3 line patches to fix
several issues such as possible null pointer dereference, PHC stopping
on max frequency, make sensor info static and SR-IOV initialization
reordering.
The remaining igb patch to fix anti-spoofing config fixes a problem
in i350 where anti spoofing configuration was written into a wrong
register.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
skb->ip_summed should be CHECKSUM_UNNECESSARY when the driver reports that
checksums were correct and CHECKSUM_NONE in any other case. They're
currently placed vice versa, which breaks the forwarding scenario. Fix it
by placing them as described above.
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For 82576 MAC type, max_adj is reported as 1000000000 ppb. However, if
this value is passed to igb_ptp_adjfreq_82576, incvalue overflows out of
INCVALUE_82576_MASK, resulting in setting of zero TIMINCA.incvalue, stopping
the PHC (instead of going at twice the nominal speed).
Fix the advertised max_adj value to the largest value hardware can handle.
As there is no min_adj value available (-max_adj is used instead), this will
also prevent stopping the clock intentionally. It's probably not a big deal,
other igb MAC types don't support stopping the clock, either.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Trivial sparse warning.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
igb is ineffective at setting a lower total VFs because:
int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs)
{
...
/* Shouldn't change if VFs already enabled */
if (dev->sriov->ctrl & PCI_SRIOV_CTRL_VFE)
return -EBUSY;
Swap init ordering.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
The max_vfs= option has always been self limiting to the number of VFs
supported by the device. fa44f2f1 added SR-IOV configuration via
sysfs, but in the process broke this self correction factor. The
failing path is:
igb_probe
igb_sw_init
if (max_vfs > 7) {
adapter->vfs_allocated_count = 7;
...
igb_probe_vfs
igb_enable_sriov(, max_vfs)
if (num_vfs > 7) {
err = -EPERM;
...
This leaves vfs_allocated_count = 7 and vf_data = NULL, so we bomb out
when igb_probe finally calls igb_reset. It seems like a really bad
idea, and somewhat pointless, to set vfs_allocated_count separate from
vf_data, but limiting max_vfs is enough to avoid the null pointer.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Fix a problem in i350 where anti spoofing configuration was written into a
wrong register.
Signed-off-by: Lior Levy <lior.levy@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
When the ixgbevf driver is opened the request to allocate MSIX irq
vectors may fail. In that case the driver will call ixgbevf_down()
which will call ixgbevf_irq_disable() to clear the HW interrupt
registers and calls synchronize_irq() using the msix_entries pointer in
the adapter structure. However, when the function to request the MSIX
irq vectors failed it had already freed the msix_entries which causes
an OOPs from using the NULL pointer in synchronize_irq().
The calls to pci_disable_msix() and to free the msix_entries memory
should not occur if device open fails. Instead they should be called
during device driver removal to balance with the call to
pci_enable_msix() and the call to allocate msix_entries memory
during the device probe and driver load.
Signed-off-by: Li Xun <xunleer.li@huawei.com>
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
fix for incorrect assignment of signed expression to unsigned variable.
Signed-off-by: Kumar Amit Mehta <gmate.amit@gmail.com>
Acked-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
VF QPs must not be released when they have steering rules attached to them.
For that end, introduce a reference count field to the QP object in the
SRIOV resource tracker which is incremented/decremented when steering rules
are attached/detached to it. QPs can be released by VF only when their
ref count is zero.
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One of the resource tracker code paths was wrongly using int and not u64
for resource tracking IDs, fix it.
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the ethtool flow steering rules cleanup to be carried out before
releasing the RX QPs.
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On the resource tracker cleanup flow, the DMFS rules must be deleted before we
destroy the QPs, else the HW may attempt doing packet steering to non existent QPs.
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the mask is wrongly set in the MAP_EQ wrapper, fix that.
Without the fix any EQ number above 511 is mapped to one below 511.
Signed-off-by: Moshe Lazer <moshel@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The error check in cpsw_probe_dt() has an '&&' where an '||' is
meant to be. This causes a NULL pointer dereference when incomplet DT
data is passed to the driver ('phy_id' property for cpsw_emac1
missing).
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Freeing netdev without free_netdev() leads to net, tx leaks.
And it may lead to dereferencing freed pointer.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
John W. Linville says:
====================
I present to you another batch of fixes intended for the 3.9 stream...
On the bluetooth bits, Gustavo says:
"I put together 3 fixes intended for 3.9, there are support for two
new devices and a NULL dereference fix in the SCO code."
Amitkumar Karwar fixes a command queueing race in mwifiex.
Bing Zhao provides a pair of mwifiex related to cleaning-up before
a shutdown.
Felix Fietkau provides an ath9k fix for a regression caused by an
earlier calibration fix, and another ath9k fix to avoid race conditions
that unnecessarily lead to chip resets.
Jussi Kivilinna prevents and skbuff leak in rtlwifi.
Stanislaw Gruszka corrects a length paramater for a DMA buffer mapping
operation in iwlegacy.
Please let me know if there are problems!
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the following warnings that happen when building with W=1 option:
drivers/net/ethernet/freescale/fec.c: In function 'fec_enet_free_buffers':
drivers/net/ethernet/freescale/fec.c:1337:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/net/ethernet/freescale/fec.c: In function 'fec_enet_alloc_buffers':
drivers/net/ethernet/freescale/fec.c:1361:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/net/ethernet/freescale/fec.c: In function 'fec_enet_init':
drivers/net/ethernet/freescale/fec.c:1631:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
One must check the result of ioremap() -- in this case it prevents potential
kernel oops when initializing TSU registers further on...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sh_mdio_init() allocates pointer to 'struct bb_info' but only stores it locally,
so that sh_mdio_release() can't free it on driver unload. Add the pointer to
'struct bb_info' to 'struct sh_eth_private', so that sh_mdio_init() can save
'bitbang' variable for sh_mdio_release() to be able to free it later...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
curr_cmd points to the command that is in processing or waiting
for its command response from firmware. If the function shutdown
happens to occur at this time we should cancel the cmd timer and
put the command back to free queue.
Cc: <stable@vger.kernel.org> # 3.8
Tested-by: Marco Cesarano <marco@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
During rmmod mwifiex_sdio processing FUNC_SHUTDOWN command is
sent to firmware. Firmware expcets only FUNC_INIT once WLAN
function is shut down.
Any command pending in the command queue should be ignored and
freed.
Cc: <stable@vger.kernel.org> # 3.8
Tested-by: Daniel Drake <dsd@laptop.org>
Tested-by: Marco Cesarano <marco@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Running the following script repeatedly on XO-4 with SD8787
produces command timeout and system lockup.
insmod mwifiex_sdio.ko
sleep 1
ifconfig eth0 up
iwlist eth0 scan &
sleep 0.5
rmmod mwifiex_sdio
mwifiex_send_cmd_async() is called for sync as well as async
commands. (mwifiex_send_cmd_sync() internally calls it for
sync command.)
"adapter->cmd_queued" gets filled inside mwifiex_send_cmd_async()
routine for both types of commands. But it is used only for sync
commands in mwifiex_wait_queue_complete(). This could lead to a
race when two threads try to queue a sync command with another
sync/async command simultaneously.
Get rid of global variable and pass command node as a parameter
to mwifiex_wait_queue_complete() to fix the problem.
Cc: <stable@vger.kernel.org> # 3.8
Reported-by: Daniel Drake <dsd@laptop.org>
Tested-by: Daniel Drake <dsd@laptop.org>
Tested-by: Marco Cesarano <marco@marvell.com>
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The beacon and multicast-buffer queues are managed by the beacon
tasklet, and the generic tx path hang check does not help in any way
here. Running it on those queues anyway can introduce some race
conditions leading to unnecessary chip resets.
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The commit 'ath9k_hw: fix calibration issues on chainmask that don't
include chain 0' changed the hardware chainmask to the chip chainmask
for the duration of the calibration, but the revert to user
configuration in the reset path runs too early.
That causes some issues with limiting the number of antennas (including
spurious failure in hardware-generated packets).
Fix this by reverting the chainmask after the essential parts of the
calibration that need the workaround, and before NF calibration is run.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Reported-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
Tested-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The UPDATE_QSTAT function introduced on February 15, 2012
in commit 1355b704b9 "bnx2x: consistent statistics after
internal driver reload" incorrectly fails to handle overflow
during addition of the lower 32-bit field of a stat.
This bug is present since 3.4-rc1 and should thus be considered
a candidate for stable 3.4+ releases.
Google-Bug-Id: 8374428
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Cc: Mintz Yuval <yuvalmin@broadcom.com>
Acked-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the hardware initialization fails in bnx2x_nic_load() after adding
napi objects, they would not be deleted. A subsequent attempt to unload
the bnx2x module detects a corruption in the napi list.
Add the missing napi deletion to the error path.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Acked-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
John W. Linville says:
====================
On the NFC bits, Samuel says:
"With this one we have:
- A fix for properly decreasing socket ack log.
- A timer and works cleanup upon NFC device removal.
- A monitoroing socket cleanup round from llcp_socket_release.
- A proper error report to pending sockets upon NFC device removal."
Regarding the Bluetooth bits, Gustavo says:
"I have these two patches for 3.9, these add support for two more devices to
the bluetooth drivers."
Along with those, we have a few wireless driver fixes...
Bing Zhao provides an mwifiex to prevent an out-of-bounds memory
access.
John Crispin offers a Kconfig fix to enable some otherwise dead code
in rt2x00. The correct symbols were added in -rc1 through a different
tree, but the symbols for enabling the wireless driver didn't match.
Larry Finger brings an rtlwifi fix for a scheduling while atomic bug,
and another fix for a reassociation problem caused by failing to
clear the BSSID after a disconnect.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix which was done in the following commit in cpsw driver has
to be taken forward to davinci emac driver as well.
commit d35162f89b
Author: Daniel Mack <zonque@gmail.com>
Date: Tue Mar 12 06:31:19 2013 +0000
net: ethernet: cpsw: fix usage of cpdma_check_free_tx_desc()
Commit fae50823d0 ("net: ethernet: davinci_cpdma: Add boundary for rx
and tx descriptors") introduced a function to check the current
allocation state of tx packets. The return value is taken into account
to stop the netqork queue on the adapter in case there are no free
slots.
However, cpdma_check_free_tx_desc() returns 'true' if there is room in
the bitmap, not 'false', so the usage of the function is wrong.
Reported-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The automated ARM build tests have shown that the tulip de4x5 driver
uses the old-style virt_to_bus() interface on some architectures.
Alpha, Sparc and PowerPC did not hit this problem, because they
use a different code path, and most other architectures actually
do provide VIRT_TO_BUS.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
commit bd329e1 ("net: cdc_ncm: do not bind to NCM compatible MBIM devices")
introduced a new policy, preferring MBIM for dual NCM/MBIM functions if
the cdc_mbim driver was enabled. This caused a regression for users
wanting to use NCM.
Devices implementing NCM backwards compatibility according to section
3.2 of the MBIM v1.0 specification allow either NCM or MBIM on a single
USB function, using different altsettings. The cdc_ncm and cdc_mbim
drivers will both probe such functions, and must agree on a common
policy for selecting either MBIM or NCM. Until now, this policy has
been set at build time based on CONFIG_USB_NET_CDC_MBIM.
Use a module parameter to set the system policy at runtime, allowing the
user to prefer NCM on systems with the cdc_mbim driver.
Cc: Greg Suarez <gsuarez@smithmicro.com>
Cc: Alexey Orishko <alexey.orishko@stericsson.com>
Reported-by: Geir Haatveit <nospam@haatveit.nu>
Reported-by: Tommi Kyntola <kynde@ts.ray.fi>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=54791
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
The Kconfig file help information incorrectly mentions that the
SMSC LAN75xx config option is for SMSC LAN95xx devices.
Signed-off-by: Robert de Vries <rhdv@xs4all.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit dc975382d2 introduces napi support
but never calls napi_disable. This will generate a kernel oops
(kernel BUG at include/linux/netdevice.h:473!) every time, when
ndo_stop is called followed by ndo_start.
Add the missing napi_diable call.
Signed-off-by: Georg Hofmann <georg@hofmannsweb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Proviously we would only restart the FEC when PHY link or duplex state
changed. PHY does not always bring down the link for speed changes, in
which case we would not detect any change and keep FEC running.
Switching link speed without restarting the FEC results in the FEC being
stuck in an indefinite state, generating error conditions for every
packet.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since v3.9-rc1 the kernel has basic support for Ralink WiSoC. The config symbols
are named slightly different than before. Fix the rt2x00 to match the new
symbols.
The commit causing this breakage is:
commit ae2b5bb657
Author: John Crispin <blogic@openwrt.org>
Date: Sun Jan 20 22:05:30 2013 +0100
MIPS: ralink: adds Kbuild files
Signed-off-by: John Crispin <blogic@openwrt.org>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
commit bd877e4 ("net: qmi_wwan: use a single bind function for
all device types") made Gobi 1K devices fail probing.
Using the number of endpoints in the default altsetting to decide
whether the function use one or two interfaces is wrong. Other
altsettings may provide more endpoints.
With Gobi 1K devices, USB interface #3's altsetting is 0 by default, but
altsetting 0 only provides one interrupt endpoint and is not sufficent
for QMI. Altsetting 1 provides all 3 endpoints required for qmi_wwan
and works with QMI. Gobi 1K layout for intf#3 is:
Interface Descriptor: 255/255/255
bInterfaceNumber 3
bAlternateSetting 0
Endpoint Descriptor: Interrupt IN
Interface Descriptor: 255/255/255
bInterfaceNumber 3
bAlternateSetting 1
Endpoint Descriptor: Interrupt IN
Endpoint Descriptor: Bulk IN
Endpoint Descriptor: Bulk OUT
Prior to commit bd877e4, we would call usbnet_get_endpoints
before giving up finding enough endpoints. Removing the early
endpoint number test and the strict functional descriptor
requirement allow qmi_wwan_bind to continue until
usbnet_get_endpoints has made the final attempt to collect
endpoints. This restores the behaviour from before commit
bd877e4 without losing the added benefit of using a single bind
function.
The driver has always required a CDC Union functional descriptor
for two-interface functions. Using the existence of this
descriptor to detect two-interface functions is the logically
correct method.
Reported-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Tested-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit d13ba512cb ("tg3: Remove
SPEED_UNKNOWN checks") cleaned up the autoneg advertisement by
removing some dead code. One effect of this change was that the
advertisement register would not be updated if autoneg is turned off.
This exposed a bug on the 5715 device w.r.t linking. The 5715 defaults
to advertise only 10Mb Full duplex. But with autoneg disabled, it needs
the configured speed enabled in the advertisement register to link up.
This patch adds the work around to advertise all speeds on the 5715 when
autoneg is disabled.
Reported-by: Marcin Miotk <marcinmiotk81@gmail.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchings says:
====================
Just the one bug fix I mentioned before, but it's a pretty important one
as it can cause silent data corruption or IOMMU page faults.
This would be suitable for stable and should apply cleanly to all the
3.x.y branches. I'm still working through testing of larger sets of
fixes.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
bond_update_speed_duplex() might sleep while calling underlying slave's
routines. Move it out of atomic context in bond_enslave() and remove it
from bond_miimon_commit() - it was introduced by commit 546add79, however
when the slave interfaces go up/change state it's their responsibility to
fire NETDEV_UP/NETDEV_CHANGE events so that bonding can properly update
their speed.
I've tested it on all combinations of ifup/ifdown, autoneg/speed/duplex
changes, remote-controlled and local, on (not) MII-based cards. All changes
are visible.
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit fae50823d0 ("net: ethernet: davinci_cpdma: Add boundary for rx
and tx descriptors") introduced a function to check the current
allocation state of tx packets. The return value is taken into account
to stop the netqork queue on the adapter in case there are no free
slots.
However, cpdma_check_free_tx_desc() returns 'true' if there is room in
the bitmap, not 'false', so the usage of the function is wrong.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Reported-by: Sven Neumann <s.neumann@raumfeld.com>
Reported-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
Tested-by: Mugunthan V N <mugunthanvnm@ti.com>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>
Tested-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using TX push when notifying the NIC of multiple new descriptors in
the ring will very occasionally cause the TX DMA engine to re-use an
old descriptor. This can result in a duplicated or partly duplicated
packet (new headers with old data), or an IOMMU page fault. This does
not happen when the pushed descriptor is the only one written.
TX push also provides little latency benefit when a packet requires
more than one descriptor.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>