linux.git/drivers/net/can/flexcan.c, branch v5.4.8

can: flexcan: add low power enter/exit acknowledgment helper

2019-12-31T15:46:05+00:00

[ Upstream commit b7603d080ffcf8689ec91ca300caf84d8dbed317 ]

The MCR[LPMACK] read-only bit indicates that FlexCAN is in a lower-power
mode (Disabled mode, Doze mode, Stop mode).

The CPU can poll this bit to know when FlexCAN has actually entered low
power mode. The low power enter/exit acknowledgment helper will reduce
code duplication for disabled mode, doze mode and stop mode.

Tested-by: Sean Nyekjaer 
Signed-off-by: Joakim Zhang 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: flexcan: poll MCR_LPM_ACK instead of GPR ACK for stop mode acknowledgment

2019-12-31T15:45:57+00:00

commit 048e3a34a2e7669bf475eb56c7345ad9d8d2b8e3 upstream.

Stop Mode is entered when Stop Mode is requested at chip level and
MCR[LPM_ACK] is asserted by the FlexCAN.

Double check with IP owner, the MCR[LPM_ACK] bit should be polled for
stop mode acknowledgment, not the acknowledgment from chip level which
is used to gate flexcan clocks.

This patch depends on:

    b7603d080ffc ("can: flexcan: add low power enter/exit acknowledgment helper")

Fixes: 5f186c257fa4 (can: flexcan: fix stop mode acknowledgment)
Tested-by: Sean Nyekjaer 
Signed-off-by: Joakim Zhang 
Cc: linux-stable  # >= v5.0
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Greg Kroah-Hartman

can: flexcan: fix possible deadlock and out-of-order reception after wakeup

2019-12-31T15:45:56+00:00

commit e707180ae2df1c87e26ec7a6fd70d07483bde7fd upstream.

When suspending, and there is still CAN traffic on the interfaces the
flexcan immediately wakes the platform again. As it should :-). But it
throws this error msg:

[ 3169.378661] PM: noirq suspend of devices failed

On the way down to suspend the interface that throws the error message
calls flexcan_suspend() but fails to call flexcan_noirq_suspend(). That
means flexcan_enter_stop_mode() is called, but on the way out of suspend
the driver only calls flexcan_resume() and skips flexcan_noirq_resume(),
thus it doesn't call flexcan_exit_stop_mode(). This leaves the flexcan
in stop mode, and with the current driver it can't recover from this
even with a soft reboot, it requires a hard reboot.

This patch fixes the deadlock when using self wakeup, by calling
flexcan_exit_stop_mode() from flexcan_resume() instead of
flexcan_noirq_resume().

This also fixes another issue: CAN frames are received out-of-order in
first IRQ handler run after wakeup.

The problem is that the wakeup latency from frame reception to the IRQ
handler (where the CAN frames are sorted by timestamp) is much bigger
than the time stamp counter wrap around time. This means it's
impossible to sort the CAN frames by timestamp.

The reason is that the controller exits stop mode during noirq resume,
which means it receives frames immediately, but interrupt handling is
still not possible.

So exit stop mode during resume stage instead of noirq resume fixes this
issue.

Fixes: de3578c198c6 ("can: flexcan: add self wakeup support")
Signed-off-by: Sean Nyekjaer 
Tested-by: Sean Nyekjaer 
Signed-off-by: Joakim Zhang 
Cc: linux-stable  # >= v5.0
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Greg Kroah-Hartman

can: flexcan: increase error counters if skb enqueueing via can_rx_offload_queue_sorted() fails

2019-11-04T20:47:22+00:00

The call to can_rx_offload_queue_sorted() may fail and return an error
(in the current implementation due to resource shortage). The passed skb
is consumed.

This patch adds incrementing of the appropriate error counters to let
the device statistics reflect that there's a problem.

Reported-by: Martin Hundebøll 
Signed-off-by: Marc Kleine-Budde

can: flexcan: disable completely the ECC mechanism

2019-11-04T20:47:20+00:00

The ECC (memory error detection and correction) mechanism can be
activated or not, controlled by the ECCDIS bit in CAN_MECR. When
disabled, updates on indications and reporting registers are stopped.
So if want to disable ECC completely, had better assert ECCDIS bit, not
just mask the related interrupts.

Fixes: cdce844865be ("can: flexcan: add vf610 support for FlexCAN")
Signed-off-by: Joakim Zhang 
Cc: linux-stable 
Signed-off-by: Marc Kleine-Budde

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2019-08-07T01:44:57+00:00

Just minor overlapping changes in the conflicts here.

Signed-off-by: David S. Miller

can: flexcan: fix stop mode acknowledgment

2019-07-24T09:16:31+00:00

To enter stop mode, the CPU should manually assert a global Stop Mode
request and check the acknowledgment asserted by FlexCAN. The CPU must
only consider the FlexCAN in stop mode when both request and
acknowledgment conditions are satisfied.

Fixes: de3578c198c6 ("can: flexcan: add self wakeup support")
Reported-by: Marc Kleine-Budde 
Signed-off-by: Joakim Zhang 
Cc: linux-stable  # >= v5.0
Signed-off-by: Marc Kleine-Budde

can: flexcan: fix an use-after-free in flexcan_setup_stop_mode()

2019-07-24T09:16:31+00:00

The gpr_np variable is still being used in dev_dbg() after the
of_node_put() call, which may result in use-after-free.

Fixes: de3578c198c6 ("can: flexcan: add self wakeup support")
Signed-off-by: Wen Yang 
Cc: linux-stable  # >= v5.0
Signed-off-by: Marc Kleine-Budde

can: flexcan: add support for DT property 'wakeup-source'

2019-07-24T08:31:55+00:00

The flexcan controller can be forced as a wakeup source by
stating that explicitly in the device's .dts file using the
"wakeup-source" boolean property.

Signed-off-by: Sean Nyekjaer 
Signed-off-by: Marc Kleine-Budde

can: flexcan: add support for PE clock source select

2019-07-24T08:31:55+00:00

Add support to select the clock source for CAN Protocol Engine (PE).
It's SoC Implementation dependent. Refer to RM for detailed definition
of each SoC. We select clock source 1 (peripheral clock) by default in
driver now, this patch adds support to parse the clock source from the DT.

Signed-off-by: Dong Aisheng 
Signed-off-by: Joakim Zhang 
Signed-off-by: Marc Kleine-Budde