c_can_start() enables interrupts way too early. The first enabling
happens when setting the control mode in c_can_chip_config() and then
again at the end of the function.
But that happens before napi_enable() and that means that an interrupt
which comes in will disable interrupts again and call napi_schedule,
which ignores the request and the later napi_enable() is not making
thinks work either. So the interface is up with all device interrupts
disabled.
Move the device interrupt after napi_enable() and add it to the other
callsites of c_can_start() in c_can_set_mode() and c_can_power_up()
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>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iEYEABECAAYFAlM6jfsACgkQjTAFq1RaXHOVTwCeOyOYOJ+Ze2x33WydGcGsvX8a
QPoAoJVAcekmL5MVbcMTTvc8QL1AebAm
=4aEp
-----END PGP SIGNATURE-----
Merge tag 'linux-can-fixes-for-3.15-20140401' of git://gitorious.org/linux-can/linux-can
linux-can-fixes-for-3.15-20140401
Marc Kleine-Budde says:
====================
this is a pull request of 16 patches for the 3.15 release cycle.
Bjorn Van Tilt contributes a patch which fixes a memory leak in usb_8dev's
usb_8dev_start_xmit()s error path. A patch by Robert Schwebel fixes a typo in
the can documentation. The remaining patches all target the c_can driver. Two
of them are by me; they add a missing netif_napi_del() and return value
checking. Thomas Gleixner contributes 12 patches, which address several
shortcomings in the driver like hardware initialisation, concurrency, message
ordering and poor performance.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no point to toggle the RX led for every packet. Especially if
we have a full FIFO we want to avoid everything we can.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The function loads the message object from the hardware to get the
payload length. The previous patch stores that information in an
array, so we can avoid the hardware access.
Remove the hardware access and move the led toggle outside of the
spinlocked region. Toggle the led only once when at least one packet
has been received.
Binary size shrinks along with the code
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
We can avoid the HW access in TX cleanup path for retrieving the DLC
of the sent package if we store the DLC in a private array.
Ideally this should be handled in the can_echo_skb functions, but I
leave that exercise to the CAN folks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
commit 4ce78a838c (can: c_can: Speed up rx_poll function) hyped a
performance improvement by reducing the access to the interrupt
pending register from a dual 16 bit to a single 16 bit access. Wow!
Thereby it crippled the driver to cast the 16 msg objects in stone,
which is completly braindead as contemporary hardware has up to 128
message objects. Supporting larger object buffers is a major surgery,
but it'd be definitely worth it especially as the driver does not
support HW message filtering ....
The logic of the "FIFO" implementation is to split the FIFO in half.
For the lower half we read the buffers and clear the interrupt pending
bit, but keep the newdat bit set, so the HW will queue above those
buffers.
When we read out the last low buffer then we reenable all the low half
buffers by clearing the newdat bit.
The upper half buffers clear the newdat and the interrupt pending bit
right away as we know that the lower half bits are clear and give us a
headstart against the hardware.
Now the implementation is:
transfer_message_object()
read_object_and_put_into_skb();
if (obj < END_OF_LOW_BUF)
clear_intpending(obj)
else if (obj > END_OF_LOW_BUF)
clear_intpending_and_newdat(obj)
else if (obj == END_OF_LOW_BUF)
clear_newdat_of_all_low_objects()
The hardware allows to avoid most of the mess simply because we can
tell the transfer_message_object() function to clear bits right away.
So we can be clever and do:
if (obj <= END_OF_LOW_BUF)
ctrl = TRANSFER_MSG | CLEAR_INTPND;
else
ctrl = TRANSFER_MSG | CLEAR_INTPND | CLEAR_NEWDAT;
transfer_message_object(ctrl)
read_object_and_put_into_skb();
if (obj == END_OF_LOW_BUF)
clear_newdat_of_all_low_objects()
So we save a complete control operation on all message objects except
the one which is the end of the low buffer. That's a few micro seconds
per object.
I'm not adding a boasting profile to that, simply because it's self
explaining.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject and commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
If every other line contains line breaks, that's a clear sign for
indentation level madness. Split out the inner loop and move the code
to a separate function. gcc creates slightly worse code for that, but
we'll fix that in the next step.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The network core does not serialize the access to the hardware. The
xmit related code lets the following happen:
CPU0 CPU1
interrupt()
do_poll()
c_can_do_tx()
Fiddle with HW and xmit()
internal data Fiddle with HW and
internal data
due the complete lack of serialization.
Add proper locking.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The rx_poll code has the following gem:
if (msg_ctrl_save & IF_MCONT_EOB)
return num_rx_pkts;
The EOB bit is the indicator for the hardware that this is the last
configured FIFO object. But this object can contain valid data, if we
manage to free up objects before the overrun case hits.
Now if the code exits due to the EOB bit set, then this buffer is
stale and the interrupt bit and NewDat bit of the buffer are still
set. Results in a nice interrupt storm unless we come into an overrun
situation where the MSGLST bit gets set.
ksoftirqd/0-3 [000] ..s. 79.124101: c_can_poll: rx_poll: val: 00008001 pend 00008001
ksoftirqd/0-3 [000] ..s. 79.124176: c_can_poll: rx_poll: val: 00008000 pend 00008000
ksoftirqd/0-3 [000] ..s. 79.124187: c_can_poll: rx_poll: val: 00008002 pend 00008002
ksoftirqd/0-3 [000] ..s. 79.124256: c_can_poll: rx_poll: val: 00008000 pend 00008000
ksoftirqd/0-3 [000] ..s. 79.124267: c_can_poll: rx_poll: val: 00008000 pend 00008000
The amazing thing is that the check of the MSGLST (aka overrun bit)
used to be after the check of the EOB bit. That was "fixed" in commit
5d0f801a2c(can: c_can: Fix RX message handling, handle lost message
before EOB). But the author of this "fix" did not even understand that
the EOB check is broken as well.
Again a simple solution: Remove
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject and commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The lost message handling is broken in several ways.
1) Clearing the message lost flag is done by writing 0 to the
message control register of the object.
#define IF_MCONT_CLR_MSGLST (0 << 14)
That clears the object buffer configuration in the worst case,
which results in a loss of the EOB flag. That leaves the FIFO chain
without a limit and causes a complete lockup of the HW
2) In case that the error skb allocation fails, the code happily
claims that it handed down a packet. Just an accounting bug, but ....
3) The code adds a lot of pointless overhead to that error case, where
we need to get stuff done as fast as possible to avoid more packet
loss.
- printk an annoying error message
- reread the object buffer for nothing
Fix is simple again:
- Use the already known MSGCTRL content and only clear the MSGLST bit
- Fix the buffer accounting by adding a proper return code
- Remove the pointless operations
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The buffer handling of c_can has been broken forever. That leads to
message reordering:
ksoftirqd/0-3 [000] ..s. 79.123776: c_can_poll: rx_poll: val: 00007fff
ksoftirqd/0-3 [000] ..s. 79.124101: c_can_poll: rx_poll: val: 00008001
What happens is:
CPU HW
queue new packet into obj 16 (0-15 are busy)
read obj 1-15
return because pending is 0
set pending obj 16 -> pending reg 8000
queue new packet into obj 1
set pending obj 1 -> pending reg 8001
So the current algorithmus reads the newest message first, which
violates the ordering rules of CAN.
Add proper handling of that situation by analyzing the contents of the
pending register for gaps.
This does NOT fix the message object corruption which can lead to
interrupt storms. Thats addressed in the next patches.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[mkl: adjusted subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The hardware has two message control interfaces, but the code only uses the
first one. So on SMP the following can be observed:
CPU0 CPU1
rx_poll()
write IF1 xmit()
write IF1
write IF1
That results in corrupted message object configurations. The TX/RX is not
globally serialized it's only serialized on a core.
Simple solution: Let RX use IF1 and TX use IF2 and all is good.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
According to the documentation the CPU must wait for CONTROL_INIT to
be cleared before writing to the baudrate registers.
Signed-off-by: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
CAN interfaces only support MTU values of 16 (CAN 2.0) and 72 (CAN FD).
Setting the MTU to other values is pointless but it does not really hurt.
With the introduction of the CAN FD support in drivers/net/can a new
function to switch the MTU for CAN FD has been introduced.
This patch makes use of this can_change_mtu() function to check for correct
MTU settings also in legacy CAN (2.0) devices.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch speeds up the rx_poll function by reducing the number of
register reads.
Replace the 32bit register read by a 16bit register read. Currently
the 32bit register read is implemented by using 2 16bit reads. This is
inefficient as we only use the lower 16bit in rx_poll.
The for loop reads the pending interrupts in every iteration. This
leads up to 16 reads of pending interrupts. The patch introduces a new
outer loop to read the pending interrupts as long as 'quota' is above 0.
This reduces the total number of reads.
The third change is to replace the for-loop by a ffs loop.
Tested on AM335x. I removed all 'static' and 'inline' from c_can.c to
see the timings for all functions. I used the function tracer with
trace_stats.
125kbit:
Function Hit Time Avg s^2
-------- --- ---- --- ---
c_can_do_rx_poll 63960 10168178 us 158.977 us 1493056 us
With patch:
c_can_do_rx_poll 63941 3764057 us 58.867 us 776162.2 us
1Mbit:
Function Hit Time Avg s^2
-------- --- ---- --- ---
c_can_do_rx_poll 69489 30049498 us 432.435 us 9271851 us
With patch:
c_can_do_rx_poll 207109 24322185 us 117.436 us 171469047 us
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The number of bytes transmitted was not updated correctly, if several CAN
messages (with different length) were transmitted in one 'bunch'. Thus
programs like 'ifconfig' showed wrong transmit byte counts. Reason was, that
the message object whose DLC is to be read was not necessarily the active one
at the time when
priv->read_reg(priv, C_CAN_IFACE(MSGCTRL_REG, 0)) & IF_MCONT_DLC_MASK;
was executed.
Signed-off-by: Holger Bechtold <Holger.Bechtold@gmx.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The c_can driver contians a callpath (c_can_poll -> c_can_state_change ->
c_can_get_berr_counter) which may call pm_runtime_get_sync() from the IRQ
handler, which is not allowed and results in "BUG: scheduling while atomic".
This problem is fixed by introducing __c_can_get_berr_counter, which will not
call pm_runtime_get_sync().
Reported-by: Andrew Glen <AGlen@bepmarine.com>
Tested-by: Andrew Glen <AGlen@bepmarine.com>
Signed-off-by: Andrew Glen <AGlen@bepmarine.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
If we handle end of block messages with higher priority than a lost message,
we can run into an endless interrupt loop.
This is reproducable with a am335x processor and "cansequence -r" at 1Mbit.
As soon as we loose a packet we can't escape from an interrupt loop.
This patch fixes the problem by handling lost packets before EOB packets.
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Conflicts:
drivers/net/ethernet/intel/e1000e/ethtool.c
drivers/net/vmxnet3/vmxnet3_drv.c
drivers/net/wireless/iwlwifi/dvm/tx.c
net/ipv6/route.c
The ipv6 route.c conflict is simple, just ignore the 'net' side change
as we fixed the same problem in 'net-next' by eliminating cached
neighbours from ipv6 routes.
The e1000e conflict is an addition of a new statistic in the ethtool
code, trivial.
The vmxnet3 conflict is about one change in 'net' removing a guarding
conditional, whilst in 'net-next' we had a netdev_info() conversion.
The iwlwifi conflict is dealing with a WARN_ON() conversion in
'net-next' vs. a revert happening in 'net'.
Signed-off-by: David S. Miller <davem@davemloft.net>
According to C_CAN documentation, the reserved bit in IFx_MASK2 register is
fixed 1.
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Bring in the 'net' tree so that we can get some ipv4/ipv6 bug
fixes that some net-next work will build upon.
Signed-off-by: David S. Miller <davem@davemloft.net>
Errors in CAN protocol (location) are reported in data[3] of the can
frame instead of data[2].
Cc: linux-stable <stable@vger.kernel.org>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add support for canbus activity led indicators on c_can devices by
calling appropriate can_led functions.
These are only enabled when CONFIG_CAN_LEDS is Y, becomes no-op
otherwise.
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Cc: AnilKumar Ch <anilkumar@ti.com>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add D_CAN raminit support to C_CAN driver to enable D_CAN RAM,
which holds all the message objects during transmission or
receiving of data. This initialization/de-initialization should
be done in synchronous with D_CAN clock.
In case of AM335X-EVM (current user of D_CAN driver) message RAM is
controlled through control module register for both instances. So
control module register details is required to initialization or
de-initialization of message RAM according to instance number.
Control module memory resource is obtained from D_CAN dt node and
instance number obtained from device tree aliases node.
This patch was tested on AM335x-EVM along with pinctrl data addition
patch, d_can dt aliases addition and control module data addition.
pinctrl data addition is not added to am335x-evm.dts (only supports
CPLD profile#0) because d_can1 is supported under CPLD profile#1.
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
[mkl: fix instance for non DT in probe, cleaned up raminit]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch fixes an oops which occurs during unloading the driver.
unregister_c_can_dev() is doing c_can/d_can module interrupts disable, which
requires module clock enable. c_can/d_can interrupts enable/disable is handled
properly in c_can_start and c_can_stop, so removing from
unregister_c_can_dev().
The problem was triggered by adding runtime PM support to the c_can driver by
this commit:
4cdd34b can: c_can: Add runtime PM support to Bosch C_CAN/D_CAN controller
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Adds suspend resume support to DCAN driver which enables
DCAN power down mode bit (PDR). Then DCAN will ack the local
power-down mode by setting PDA bit in STATUS register.
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add Runtime PM support to C_CAN/D_CAN controller. The runtime PM
APIs control clocks for C_CAN/D_CAN IP and prevent access to the
register of C_CAN/D_CAN IP when clock is turned off.
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch marks the bittiming_const pointer as in the struct can_pric as
"const". This allows us to mark the struct can_bittiming_const in the CAN
drivers as "const", too.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Conflicts:
net/ipv6/route.c
This deals with a merge conflict between the net-next addition of the
inetpeer network namespace ops, and Thomas Graf's bug fix in
2a0c451ade which makes sure we don't
register /proc/net/ipv6_route before it is actually safe to do so.
Signed-off-by: David S. Miller <davem@davemloft.net>
(CAN_CTRLMODE_LISTENONLY & CAN_CTRLMODE_LOOPBACK) is (0x02 & 0x01) which
is zero so the condition is never true. The intent here was to test
that both flags were set.
Cc: <stable@kernel.org> # 2.6.39+
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
c_can uses overlay structure for accessing c_can module registers.
With this kind of implementation it is difficult to add one more ip
which is similar to c_can in functionality but different register
offsets.
This patch changes the overlay structure implementation to an array
with register offset as index. This way we can overcome the above
limitation.
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Fix the issue of C_CAN interrupts getting disabled forever when canconfig
utility is used multiple times. According to NAPI usage we disable all
the hardware interrupts in ISR and re-enable them in poll(). Current
implementation calls napi_enable() after hardware interrupts are enabled.
If we get any interrupts between these two steps then we do not process
those interrupts because napi is not enabled. Mostly these interrupts
come because of STATUS is not 0x7 or ERROR interrupts. If napi_enable()
happens before HW interrupts enabled then c_can_poll() function will be
called eventual re-enabling.
This patch moves the napi_enable() call before interrupts enabled.
Cc: stable@kernel.org # 2.6.39+
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch fixes an interrupt thrash issue with c_can driver.
In c_can_isr() function interrupts are disabled and enabled only in
c_can_poll() function. c_can_isr() & c_can_poll() both read the
irqstatus flag. However, irqstatus is always read as 0 in c_can_poll()
because all C_CAN interrupts are disabled in c_can_isr(). This causes
all interrupts to be re-enabled in c_can_poll() which in turn causes
another interrupt since the event is not really handled. This keeps
happening causing a flood of interrupts.
To fix this, read the irqstatus register in isr and use the same cached
value in the poll function.
Cc: stable@kernel.org # 2.6.39+
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch fixes an issue with transmit routine, which causes
"can_put_echo_skb: BUG! echo_skb is occupied!" message when
using "cansequence -p" on D_CAN controller.
In c_can driver, while transmitting packets tx_echo flag holds
the no of can frames put for transmission into the hardware.
As the comment above c_can_do_tx() indicates, if we find any packet
which is not transmitted then we should stop looking for more.
In the current implementation this is not taken care of causing the
said message.
Also, fix the condition used to find if the packet is transmitted
or not. Current code skips the first tx message object and ends up
checking one extra invalid object.
While at it, fix the comment on top of c_can_do_tx() to use the
terminology "packet" instead of "package" since it is more
standard.
Cc: stable@kernel.org # 2.6.39+
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Remove duplicated #include('s) in
drivers/net/can/c_can/c_can.c
drivers/net/can/c_can/c_can_platform.c
Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/net/.
This patch removes them.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current SocketCAN implementation for the Bosch c_can cell doesn't
account the TX bytes correctly, because it calls
c_can_inval_msg_object() (which clears the msg ctrl register) before
reading the DLC value:
for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
msg_obj_no = get_tx_echo_msg_obj(priv);
c_can_inval_msg_object(dev, 0, msg_obj_no);
val = c_can_read_reg32(priv, &priv->regs->txrqst1);
if (!(val & (1 << msg_obj_no))) {
can_get_echo_skb(dev,
msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
stats->tx_bytes += priv->read_reg(priv,
&priv->regs->ifregs[0].msg_cntrl)
& IF_MCONT_DLC_MASK;
stats->tx_packets++;
}
}
So, we will always read 0 for the DLC value and "ifconfig" will report
*0* TX Bytes.
The fix is quite easy: Just move c_can_inval_msg_object() to the end of
the if() statement. So:
* We only call c_can_inval_msg_object() if the message was
actually transmitted
* We read out the DLC value _before_ clearing the msg ctrl
register
Signed-off-by: Jan Altenberg <jan@linutronix.de>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch disables the one shot mode, until the driver has been fixed and
tested to support it.
> I'm quite sure I've seen a situation where msg_obj 17 "seemed" to be
> pending, while msg_obj 18 and 19 already have been transmitted. But
> in that case, I enabled ONESHOT for the can interface, which enables
> the DA mode (automatic retransmission is disabled).
Reported-by: Jan Altenberg <jan@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I ran into some trouble while testing the SocketCAN driver for the BOSCH
C_CAN controller. The interface is not correctly initialized, if I put
some CAN traffic on the line, _while_ the interface is being started
(which means: the interface doesn't come up correcty, if there's some RX
traffic while doing 'ifconfig can0 up').
The current implementation enables the controller interrupts _before_
doing the basic c_can configuration. I think, this should be done the
other way round.
The patch below fixes things for me.
Signed-off-by: Jan Altenberg <jan@linutronix.de>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Bosch C_CAN controller is a full-CAN implementation which is compliant
to CAN protocol version 2.0 part A and B. Bosch C_CAN user manual can be
obtained from:
http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/users_manual_c_can.pdf
This patch adds the support for this controller.
The following are the design choices made while writing the controller
driver:
1. Interface Register set IF1 has be used only in the current design.
2. Out of the 32 Message objects available, 16 are kept aside for RX
purposes and the rest for TX purposes.
3. NAPI implementation is such that both the TX and RX paths function
in polling mode.
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Gleixner