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47,446 commits

Author SHA1 Message Date
Alexander Aring
652355c5bd at86rf230: use devm_request_irq
This patch replace request_irq with devm_request_irq. With
devm_request_irq we don't need to care about freeing the irq.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:20:33 -04:00
Alexander Aring
8eba0eefae at86rf230: remove irq_type in request_irq
We don't need to set these values at request_irq. The interrupt line is
already configured to same value like irq_get_trigger_type returned.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:20:32 -04:00
Alexander Aring
4af619ae2c at86rf230: use irq_get_trigger_type
This patch removes the platform data for the irq_type. We use instead
the irq_get_trigger_type function to get these flags which should
already configured by the interrupt controller.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:20:32 -04:00
Narender Kumar
ab15f86b8d bnx2x: Fix failure to configure VF multicast filters
Commit 2dc33bbc "bnx2x: Remove the sriov VFOP mechanism" caused a regression,
preventing VFs from configuring multicast filters.

Signed-off-by: Naredner Kumar <narender.kumar@qlogic.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:15:27 -04:00
Yuval Mintz
1a3d94240b bnx2x: Fix vlan credit issues for VFs
Starting with commit 2dc33bbc "bnx2x: Remove the sriov VFOP mechanism",
the bnx2x started enforcing vlan credits for all vlan configurations.
This exposed 2 issues:
  - Vlan credits are not returned once a VF is removed; this causes a leak
    of credits, and eventually will lead to VFs with no vlan credits.
  - A vlan credit must be set aside for the Hypervisor to use, and should
    not be visible to the VF.

Although linux VFs at the moment do not support vlan configuration [from the
VF side] which causes them to be resilient to this sort of issue, Windows VF
over linux hypervisors might fail to load as the vlan credits become depleted.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:15:27 -04:00
Yuval Mintz
e2a367f8e3 bnx2x: Memory leak during VF removal
When removing a VF interface, the driver fails to release that VF's mailbox
and bulletin board allocated memory.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-26 12:15:27 -04:00
Hans de Goede
ffa216bb5e brcmfmac: Fix brcmf_chip_ai_coredisable not applying reset bits to BCMA_IOCTL
brcmfmac has been broken on my cubietruck with a BCM43362:

brcmfmac: brcmf_chip_recognition: found AXI chip: BCM43362, rev=1
brcmfmac: brcmf_c_preinit_dcmds: Firmware version = wl0:
        Apr 22 2013 14:50:00 version 5.90.195.89.6 FWID 01-b30a427d

since commit 5303626103: "brcmfmac: update core reset and disable routines".

The problem is that since this commit brcmf_chip_ai_resetcore no longer sets
BCMA_IOCTL itself before bringing the core out of reset, instead relying on
brcmf_chip_ai_coredisable to do so. But brcmf_chip_ai_coredisable is a nop
of the chip is already in reset. This patch modifies brcmf_chip_ai_coredisable
to always set BCMA_IOCTL even if the core is already in reset.

This fixes brcmfmac hanging in firmware loading on my board.

Cc: stable@vger.kernel.org # v3.14
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-04-24 21:46:22 -04:00
Rajkumar Manoharan
8c7ae357cc ath9k: fix race in setting ATH_OP_INVALID
The commit "ath9k: move sc_flags to ath_common" moved setting
ATH_OP_INVALID flag below ieee80211_register_hw. This is causing
the flag never being cleared randomly as the drv_start is called
prior to setting flag. Fix this by setting the flag prior to
register_hw.

Signed-off-by: Rajkumar Manoharan <rmanohar@qti.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-04-24 21:46:22 -04:00
John W. Linville
bb0f8609ba Revert "mwifiex: add firmware dump feature for PCIe"
This reverts commit e050c76fcf.

I'm not sure what crack pipe I was using when I merged this...

Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-04-24 21:33:55 -04:00
Carolyn Wyborny
a1f6347328 igb: Change memcpy to struct assignment
This patch fixes issue found by updated coccicheck.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:41:17 -07:00
Carolyn Wyborny
f6f38e270e igb: Replace 1/0 return values with true/false
This patch fixes issues found by updated coccicheck.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:41:17 -07:00
Carolyn Wyborny
be28b63506 igb: Cleanups to remove unneeded extern declaration
This patch fixes WARNING:AVOID_EXTERNS found by checkpatch file check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:41:16 -07:00
Carolyn Wyborny
cd1631cee3 igb: Cleanups to replace deprecated DEFINE_PCI_DEVICE_TABLE
This patch changes implementation to remove use of DEFINE_PCI_DEVICE_TABLE.
This patch fixes WARNING:DEFINE_PCI_DEVICE_TABLE

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:41:16 -07:00
Carolyn Wyborny
6dd6d2b783 igb: Cleanups to fix static initialization
This patch fixes ERROR:INITIALISED_STATIC from checkpatch file check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:41:16 -07:00
Carolyn Wyborny
0d451e7956 igb: Cleanups to fix msleep warnings
This patch fixes WARNING:MSLEEP found by checkpatch check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:41:15 -07:00
Carolyn Wyborny
c502ea2ea8 igb: Cleanups to fix line length warnings
This patch fixes WARNING:LONG_LINE found with checkpatch check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:26:30 -07:00
Carolyn Wyborny
da1f1dfeb3 igb: Cleanups to remove return parentheses
This patch fixes ERROR:RETURN_PARENTHESES from checkpatch file check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:26:29 -07:00
Carolyn Wyborny
b26141d47a igb: Cleanups to fix missing break in switch statements
This patch fixes WARNING:MISSING_BREAK found with checkpatch check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:26:28 -07:00
Carolyn Wyborny
81ad807b26 igb: Cleanups to fix assignment in if error
This patch fixes ERROR:ASSIGN_IN_IF found with checkpatch file check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:26:28 -07:00
Carolyn Wyborny
e52c0f960c igb: Cleanups to change comment style on license headers
This patch fixes WARNING:NETWORKING_BLOCK_COMMENT_STYLE from checkpatch file check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:26:27 -07:00
Carolyn Wyborny
bed83e94d0 igb: Cleanups to fix for trailing statement
This patch fixes WARNING:TRAILING_STATEMENT from checkpatch file check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:26:26 -07:00
Carolyn Wyborny
c4917c6ffe igb: Cleanups to fix pointer location error
This patch fixes ERROR:POINTER_LOCATION from checkpatch file check.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
2014-04-24 17:26:26 -07:00
Kurt Van Dijck
0f8dced5ef can: softing: remove unused sysfs attributes
'frequency' indicates the embedded cpu's frequency, but that
should not be necessary for any purpose.
'txpending' is an attribute for debugging.

Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-25 00:09:03 +02:00
Kurt Van Dijck
ec2e11ed3f can: softing: drop 'channel' sysfs attribute
netdev->dev_id obsoletes this property.
None of the remaining properties contribute to udev detection methods.
The regular calls for the sysfs group can thus safely be restored.

Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-25 00:08:58 +02:00
Alexander Stein
abcd7f750a can: c_can: Add support for eg20t (pch_can)
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-25 00:08:43 +02:00
Olivier Sobrie
8e964fe21d can: usb: Kconfig: Improve help for CAN_KVASER_USB
Add two new USB devices supported by the driver and fix bad
english.

Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:54:16 +02:00
Olivier Sobrie
b4f20130af can: kvaser_usb: add support for Kvaser Leaf v2 and usb mini PCIe
This patch adds support for the Kvaser Leaf v2 and Leaf usb mini
PCIe card.

Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:54:16 +02:00
Olivier Sobrie
e59e36e733 can: kvaser_usb: add retries/timeout to kvaser_usb_wait_msg()
On some Kvaser hardware, the firmware returns extra messages after the
request for card info. For instance on a Leaf Light v2:
  --> CMD_GET_CARD_INFO
  <-- CMD_USB_THROTTLE
  <-- CMD_GET_CARD_INFO2
  <-- CMD_GET_CARD_INFO_REQ
When it happens, the probing function fails because we only read
the first usb message.

To overcome this issue, we add a mechanism of retries to the
kvaser_usb_wait_msg() function.

I tested this patch with the following hardware:
 - Kvaser Leaf Light
 - Kvaser Leaf Light v2
 - Kvaser USBCan R

This patch is necessary for the Leaf Light v2 hardware.

Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:54:16 +02:00
Stefano Babic
869ba1e67a can: move SPI drivers into a separate directory
Create a directory for all CAN drivers using SPI and move mcp251x driver there.

Signed-off-by: Stefano Babic <sbabic@denx.de>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:54:16 +02:00
Alexander Shiyan
ee967fffd9 can: mcp251x: Improve mcp251x_hw_probe()
This patch adds check for mcp251x_hw_reset() result on startup and
removes unnecessary checking for CANSTAT register since this value
is being checked in mcp251x_hw_reset().

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Tested-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:54:15 +02:00
Alexander Shiyan
ff06d611a3 can: mcp251x: Improve mcp251x_hw_reset()
The MCP251x utilizes an oscillator startup timer (OST), which holds the
chip in reset, to insure that the oscillator has stabilized before the
internal state machine begins to operate. The OST maintains reset for
the first 128 OSC clock cycles after power up or reset.
So, this patch removes unnecessary loops and reduce delay for power on
and reset to the safe value.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Tested-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:54:15 +02:00
Alexander Shiyan
31473c286c can: mcp251x: Check return value of spi_setup()
This patch moves setup of SPI bus a bit earlier and adds check for spi_setup()
result to be sure SPI bus is communicating with the device properly.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Tested-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:54:15 +02:00
Tobias Klauser
d42f157b34 Altera TSE: Remove unnecessary cast of void pointers
No need to cast void pointers.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24 16:51:41 -04:00
Alexander Stein
367525c8c2 can: slcan: Fix spinlock variant
slc_xmit is called within softirq context and locks sl->lock, but
slcan_write_wakeup is not softirq context, so we need to use
spin_[un]lock_bh!
Detected using kernel lock debugging mechanism.

Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:32:41 +02:00
Oliver Hartkopp
d482443244 can: fix return value from can_get_bittiming()
When trying to set a data bitrate on non CAN FD devices the 'ip' tool
answers with:

	RTNETLINK answers: Unknown error 524

Rename '-ENOTSUPP' to '-EOPNOTSUPP' so that 'ip' answers correctly:

       RTNETLINK answers: Operation not supported

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:30:39 +02:00
Oliver Hartkopp
a9edcdedbd can: sja1000_isa: add locking for indirect register access mode
When accessing the SJA1000 controller registers in the indirect access mode,
writing the register number and reading/writing the data has to be an atomic
attempt.

As the sja1000_isa driver is an old style driver with a fixed number of
instances the locking variable depends on the same index like all the other
configuration elements given on the module command line.

As a positive side effect dev->dev_id is populated by the instance index,
which was missing in 3e66d0138c ("can: populate netdev::dev_id for udev
discrimination").

Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:22:53 +02:00
Wolfgang Grandegger
78c181bc8a can: c_can_pci: enable PCI bus master only for MSI
Coverity complains that c_can_pci_probe() calls pci_enable_msi() without
checking the result:

CID 712278 (#1 of 1): Unchecked return value (CHECKED_RETURN) 3. check_return:
Calling pci_enable_msi_block without checking return value (as is done
elsewhere 88 out of 105 times).
 88        pci_enable_msi(pdev);

This is CID 712278.

Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Reported-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:22:52 +02:00
Nicolas Dichtel
f01ec1c017 vxlan: add x-netns support
This patch allows to switch the netns when packet is encapsulated or
decapsulated.
The vxlan socket is openned into the i/o netns, ie into the netns where
encapsulated packets are received. The socket lookup is done into this netns to
find the corresponding vxlan tunnel. After decapsulation, the packet is
injecting into the corresponding interface which may stand to another netns.

When one of the two netns is removed, the tunnel is destroyed.

Configuration example:
ip netns add netns1
ip netns exec netns1 ip link set lo up
ip link add vxlan10 type vxlan id 10 group 239.0.0.10 dev eth0 dstport 0
ip link set vxlan10 netns netns1
ip netns exec netns1 ip addr add 192.168.0.249/24 broadcast 192.168.0.255 dev vxlan10
ip netns exec netns1 ip link set vxlan10 up

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-24 16:18:26 -04:00
Wolfram Sang
f323d7a1d2 can: c_can: use proper type for 'instance'
Commit 6439fbce10 (can: c_can: fix error checking of priv->instance in
probe()) found the warning but applied a suboptimal solution. Since, both
pdev->id and of_alias_get_id() return integers, it makes sense to convert the
variable to an integer and avoid the cast.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:01 +02:00
Thomas Gleixner
939415973f can: c_can: Speed up tx buffer invalidation
It's suffcient to kill the TXIE bit in the message control register
even if the documentation of C and D CAN says that it's not allowed to
do that while MSGVAL is set. Reality tells a different story and this
change gives us another 2% of CPU back for not waiting on I/O.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:01 +02:00
Thomas Gleixner
35bdafb576 can: c_can: Remove tx locking
Mark suggested to use one IF for the softirq and the other for the
xmit function to avoid the xmit lock.

That requires to write the frame into the interface first, then handle
the echo skb and store the dlc before committing the TX request to the
message ram.

We use an atomic to handle the active buffers instead of reading the
MSGVAL register as thats way faster especially on PCH/x86.

Suggested-by: Mark <mark5@del-llc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:01 +02:00
Thomas Gleixner
d48071be6c can: c_can: Use proper u32 variables in c_can_write_msg_object()
Instead of obfuscating the code by artificial 16 bit splits use the
proper 32 bit assignments and split the result when writing to the
interface.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:01 +02:00
Thomas Gleixner
23ef0a895d can: c_can: Cleanup c_can_write_msg_object()
Remove the MASK from the TX transfer side.

Make the code readable and get rid of the annoying IFX_WRITE_XXX_16BIT
macros which are just obfuscating the code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:01 +02:00
Thomas Gleixner
7af28630b8 can: c_can: Cleanup c_can_msg_obj_put/get()
Sigh!

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
b07faaaf1f can: c_can: Cleanup c_can_inval_msg_object()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
8ff2de0fb4 can: c_can: Cleanup setup of receive buffers
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
4fb6dccd13 can: c_can: Cleanup c_can_read_msg_object()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
2d5f4f8569 can: c_can: Cleanup irq enable/disable
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
d61d09de02 can: c_can: Work around C_CAN RX wreckage
Alexander reported that the new optimized handling of the RX fifo
causes random packet loss on Intel PCH C_CAN hardware.

After a few fruitless debugging sessions I got hold of a PCH (eg20t)
afflicted system. That machine does not have the CAN interface wired
up, but it was possible to reproduce the issue with the HW loopback
mode.

As Alexander observed correctly, clearing the NewDat flag along with
reading out the message buffer causes that issue on C_CAN, while D_CAN
handles that correctly.

Instead of restoring the original message buffer handling horror the
following workaround solves the issue:

    transfer buffer to IF without clearing the NewDat
    handle the message
    clear NewDat bit

That's similar to the original code but conditional for C_CAN.

I really wonder why all user manuals (C_CAN, Intel PCH and some more)
recommend to clear the NewDat bit right away. The knows it all Oracle
operated by Gurgle does not unearth any useful information either. I
simply cannot believe that we are the first to uncover that HW issue.

Reported-and-tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00
Thomas Gleixner
2b9aecdce2 can: c_can: Disable rx split as workaround
The RX buffer split causes packet loss in the hardware:

What happens is:

RX Packet 1 --> message buffer 1 (newdat bit is not cleared)
RX Packet 2 --> message buffer 2 (newdat bit is not cleared)
RX Packet 3 --> message buffer 3 (newdat bit is not cleared)
RX Packet 4 --> message buffer 4 (newdat bit is not cleared)
RX Packet 5 --> message buffer 5 (newdat bit is not cleared)
RX Packet 6 --> message buffer 6 (newdat bit is not cleared)
RX Packet 7 --> message buffer 7 (newdat bit is not cleared)
RX Packet 8 --> message buffer 8 (newdat bit is not cleared)

Clear newdat bit in message buffer 1
Clear newdat bit in message buffer 2
Clear newdat bit in message buffer 3
Clear newdat bit in message buffer 4
Clear newdat bit in message buffer 5
Clear newdat bit in message buffer 6
Clear newdat bit in message buffer 7
Clear newdat bit in message buffer 8

Now if during that clearing of newdat bits, a new message comes in,
the HW gets confused and drops it.

It does not matter how many of them you clear. I put a delay between
clear of buffer 1 and buffer 2 which was long enough that the message
should have been queued either in buffer 1 or buffer 9. But it did not
show up anywhere. The next message ended up in buffer 1. So the
hardware lost a packet of course without telling it via one of the
error handlers.

That does not happen on all clear newdat bit events. I see one of 10k
packets dropped in the scenario which allows us to reproduce. But the
trace looks always the same.

Not splitting the RX Buffer avoids the packet loss but can cause
reordering. It's hard to trigger, but it CAN happen.

With that mode we use the HW as it was probably designed for. We read
from the buffer 1 upwards and clear the buffer as we get the
message. That's how all microcontrollers use it. So I assume that the
way we handle the buffers was never really tested. According to the
public documentation it should just work :)

Let the user decide which evil is the lesser one.

[ Oliver Hartkopp: Provided a sane config option and help text and
  made me switch to favour potential and unlikely reordering over
  packet loss ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-04-24 22:09:00 +02:00