linux-toradex.git/drivers/net/can, branch v4.20

can: flexcan: use can_rx_offload_queue_sorted() for flexcan_irq_bus_*()

2018-11-09T16:33:33+00:00

Currently, in case of bus error, driver will generate error message and put
in the tail of the message queue. To avoid confusions, this change should
place the bus related messages in proper order.

Signed-off-by: Oleksij Rempel 
Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: rx-offload: rename can_rx_offload_irq_queue_err_skb() to can_rx_offload_queue_tail()

2018-11-09T16:33:32+00:00

This function has nothing todo with error.

Signed-off-by: Oleksij Rempel 
Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: flexcan: handle tx-complete CAN frames via rx-offload infrastructure

2018-11-09T16:33:32+00:00

Current flexcan driver will put TX-ECHO in regular unsorted way, in
this case TX-ECHO can come after the response to the same TXed message.
In some cases, for example for J1939 stack, things will break.
This patch is using new rx-offload API to put the messages just in the
right place.

Signed-off-by: Oleksij Rempel 
Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: rx-offload: introduce can_rx_offload_get_echo_skb() and can_rx_offload_queue_sorted() functions

2018-11-09T16:20:49+00:00

Current CAN framework can't guarantee proper/chronological order
of RX and TX-ECHO messages. To make this possible, drivers should use
this functions instead of can_get_echo_skb().

Signed-off-by: Oleksij Rempel 
Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: dev: __can_get_echo_skb(): print error message, if trying to echo non existing skb

2018-11-09T16:20:46+00:00

Prior to echoing a successfully transmitted CAN frame (by calling
can_get_echo_skb()), CAN drivers have to put the CAN frame (by calling
can_put_echo_skb() in the transmit function). These put and get function
take an index as parameter, which is used to identify the CAN frame.

A driver calling can_get_echo_skb() with a index not pointing to a skb
is a BUG, so add an appropriate error message.

Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb is accessed out of bounds

2018-11-09T16:20:43+00:00

If the "struct can_priv::echo_skb" is accessed out of bounds would lead
to a kernel crash. Better print a sensible warning message instead and
try to recover.

Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: dev: __can_get_echo_skb(): replace struct can_frame by canfd_frame to access frame length

2018-11-09T16:20:40+00:00

This patch replaces the use of "struct can_frame::can_dlc" by "struct
canfd_frame::len" to access the frame's length. As it is ensured that
both structures have a compatible memory layout for this member this is
no functional change. Futher, this compatibility is documented in a
comment.

Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: dev: can_get_echo_skb(): factor out non sending code to __can_get_echo_skb()

2018-11-09T16:20:34+00:00

This patch factors out all non sending parts of can_get_echo_skb() into
a seperate function __can_get_echo_skb(), so that it can be re-used in
an upcoming patch.

Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: flexcan: remove not needed struct flexcan_priv::tx_mb and struct flexcan_priv::tx_mb_idx

2018-11-09T16:20:29+00:00

The previous patch changes the TX path to always use the last mailbox
regardless of the used offload scheme (rx-fifo or timestamp based). This
means members "tx_mb" and "tx_mb_idx" of the struct flexcan_priv don't
depend on the offload scheme, so replace them by compile time constants.

Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

can: flexcan: Always use last mailbox for TX

2018-11-09T16:20:23+00:00

Essentially this patch moves the TX mailbox to position 63, regardless
of timestamp based offloading or RX FIFO. So mainly the iflag register
usage regarding TX has changed. The rest is consolidating RX FIFO and
timestamp offloading as they now use both the same TX mailbox.

The reason is a very annoying behavior regarding sending RTR frames when
_not_ using RX FIFO:

If a TX mailbox sent a RTR frame it becomes a RX mailbox. For that
reason flexcan_irq disables the TX mailbox again. But if during the time
the RTR was sent and the TX mailbox is disabled a new CAN frames is
received, it is lost without notice. The reason is that so-called
"Move-in" process starts from the lowest mailbox which happen to be a TX
mailbox set to EMPTY.

Steps to reproduce (I used an imx7d):
1. generate regular bursts of messages
2. send a RTR from flexcan with higher priority than burst messages every
   1ms, e.g. cangen -I 0x100 -L 0 -g 1 -R can0
3. notice a lost message without notification after some seconds

When running an iperf in parallel this problem is occurring even more
frequently. Using filters is not possible as at least one single CAN-ID
is allowed. Handling the TX MB during RX is also not possible as there
is no race-free disable of RX MB.

There is still a slight window when the described problem can occur. But
for that all RX MB must be in use which is essentially next to an
overrun. Still there will be no indication if it ever occurs.

Signed-off-by: Alexander Stein 
Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde