| 5ba7258f | 25-Oct-2024 |
Marc Kleine-Budde <mkl@pengutronix.de> |
can: mcp251xfd: mcp251xfd_ring_alloc(): fix coalescing configuration when switching CAN modes
commit eb9a839b3d8a989be5970035a5cf29bcd6ffd24d upstream.
Since commit 50ea5449c563 ("can: mcp251xfd: f
can: mcp251xfd: mcp251xfd_ring_alloc(): fix coalescing configuration when switching CAN modes
commit eb9a839b3d8a989be5970035a5cf29bcd6ffd24d upstream.
Since commit 50ea5449c563 ("can: mcp251xfd: fix ring configuration
when switching from CAN-CC to CAN-FD mode"), the current ring and
coalescing configuration is passed to can_ram_get_layout(). That fixed
the issue when switching between CAN-CC and CAN-FD mode with
configured ring (rx, tx) and/or coalescing parameters (rx-frames-irq,
tx-frames-irq).
However 50ea5449c563 ("can: mcp251xfd: fix ring configuration when
switching from CAN-CC to CAN-FD mode"), introduced a regression when
switching CAN modes with disabled coalescing configuration: Even if
the previous CAN mode has no coalescing configured, the new mode is
configured with active coalescing. This leads to delayed receiving of
CAN-FD frames.
This comes from the fact, that ethtool uses usecs = 0 and max_frames =
1 to disable coalescing, however the driver uses internally
priv->{rx,tx}_obj_num_coalesce_irq = 0 to indicate disabled
coalescing.
Fix the regression by assigning struct ethtool_coalesce
ec->{rx,tx}_max_coalesced_frames_irq = 1 if coalescing is disabled in
the driver as can_ram_get_layout() expects this.
Reported-by: https://github.com/vdh-robothania
Closes: https://github.com/raspberrypi/linux/issues/6407
Fixes: 50ea5449c563 ("can: mcp251xfd: fix ring configuration when switching from CAN-CC to CAN-FD mode")
Cc: stable@vger.kernel.org
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241025-mcp251xfd-fix-coalesing-v1-1-9d11416de1df@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
show more ...
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| 3a2532d8 | 11-Jan-2023 |
Marc Kleine-Budde <mkl@pengutronix.de> |
can: mcp251xfd: move mcp251xfd_timestamp_start()/stop() into mcp251xfd_chip_start/stop()
commit a7801540f325d104de5065850a003f1d9bdc6ad3 upstream.
The mcp251xfd wakes up from Low Power or Sleep Mod
can: mcp251xfd: move mcp251xfd_timestamp_start()/stop() into mcp251xfd_chip_start/stop()
commit a7801540f325d104de5065850a003f1d9bdc6ad3 upstream.
The mcp251xfd wakes up from Low Power or Sleep Mode when SPI activity
is detected. To avoid this, make sure that the timestamp worker is
stopped before shutting down the chip.
Split the starting of the timestamp worker out of
mcp251xfd_timestamp_init() into the separate function
mcp251xfd_timestamp_start().
Call mcp251xfd_timestamp_init() before mcp251xfd_chip_start(), move
mcp251xfd_timestamp_start() to mcp251xfd_chip_start(). In this way,
mcp251xfd_timestamp_stop() can be called unconditionally by
mcp251xfd_chip_stop().
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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| 5ea24ddc | 11-Jan-2023 |
Marc Kleine-Budde <mkl@pengutronix.de> |
can: mcp251xfd: rx: add workaround for erratum DS80000789E 6 of mcp2518fd
[ Upstream commit 24436be590c6fbb05f6161b0dfba7d9da60214aa ]
This patch tries to works around erratum DS80000789E 6 of the
can: mcp251xfd: rx: add workaround for erratum DS80000789E 6 of mcp2518fd
[ Upstream commit 24436be590c6fbb05f6161b0dfba7d9da60214aa ]
This patch tries to works around erratum DS80000789E 6 of the
mcp2518fd, the other variants of the chip family (mcp2517fd and
mcp251863) are probably also affected.
In the bad case, the driver reads a too large head index. In the
original code, the driver always trusted the read value, which caused
old, already processed CAN frames or new, incompletely written CAN
frames to be (re-)processed.
To work around this issue, keep a per FIFO timestamp [1] of the last
valid received CAN frame and compare against the timestamp of every
received CAN frame. If an old CAN frame is detected, abort the
iteration and mark the number of valid CAN frames as processed in the
chip by incrementing the FIFO's tail index.
Further tests showed that this workaround can recognize old CAN
frames, but a small time window remains in which partially written CAN
frames [2] are not recognized but then processed. These CAN frames
have the correct data and time stamps, but the DLC has not yet been
updated.
[1] As the raw timestamp overflows every 107 seconds (at the usual
clock rate of 40 MHz) convert it to nanoseconds with the
timecounter framework and use this to detect stale CAN frames.
Link: https://lore.kernel.org/all/BL3PR11MB64844C1C95CA3BDADAE4D8CCFBC99@BL3PR11MB6484.namprd11.prod.outlook.com [2]
Reported-by: Stefan Althöfer <Stefan.Althoefer@janztec.com>
Closes: https://lore.kernel.org/all/FR0P281MB1966273C216630B120ABB6E197E89@FR0P281MB1966.DEUP281.PROD.OUTLOOK.COM
Tested-by: Stefan Althöfer <Stefan.Althoefer@janztec.com>
Tested-by: Thomas Kopp <thomas.kopp@microchip.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| 6cdc3fc4 | 11-Jan-2023 |
Marc Kleine-Budde <mkl@pengutronix.de> |
can: mcp251xfd: clarify the meaning of timestamp
[ Upstream commit e793c724b48ca8cae9693bc3be528e85284c126a ]
The mcp251xfd chip is configured to provide a timestamp with each
received and transmit
can: mcp251xfd: clarify the meaning of timestamp
[ Upstream commit e793c724b48ca8cae9693bc3be528e85284c126a ]
The mcp251xfd chip is configured to provide a timestamp with each
received and transmitted CAN frame. The timestamp is derived from the
internal free-running timer, which can also be read from the TBC
register via SPI. The timer is 32 bits wide and is clocked by the
external oscillator (typically 20 or 40 MHz).
To avoid confusion, we call this timestamp "timestamp_raw" or "ts_raw"
for short.
Using the timecounter framework, the "ts_raw" is converted to 64 bit
nanoseconds since the epoch. This is what we call "timestamp".
This is a preparation for the next patches which use the "timestamp"
to work around a bug where so far only the "ts_raw" is used.
Tested-by: Stefan Althöfer <Stefan.Althoefer@janztec.com>
Tested-by: Thomas Kopp <thomas.kopp@microchip.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| bf501ab4 | 11-Jan-2023 |
Marc Kleine-Budde <mkl@pengutronix.de> |
can: mcp251xfd: rx: prepare to workaround broken RX FIFO head index erratum
[ Upstream commit 85505e585637a737e4713c1386c30e37c325b82e ]
This is a preparatory patch to work around erratum DS8000078
can: mcp251xfd: rx: prepare to workaround broken RX FIFO head index erratum
[ Upstream commit 85505e585637a737e4713c1386c30e37c325b82e ]
This is a preparatory patch to work around erratum DS80000789E 6 of
the mcp2518fd, the other variants of the chip family (mcp2517fd and
mcp251863) are probably also affected.
When handling the RX interrupt, the driver iterates over all pending
FIFOs (which are implemented as ring buffers in hardware) and reads
the FIFO header index from the RX FIFO STA register of the chip.
In the bad case, the driver reads a too large head index. In the
original code, the driver always trusted the read value, which caused
old CAN frames that were already processed, or new, incompletely
written CAN frames to be (re-)processed.
Instead of reading and trusting the head index, read the head index
and calculate the number of CAN frames that were supposedly received -
replace mcp251xfd_rx_ring_update() with mcp251xfd_get_rx_len().
The mcp251xfd_handle_rxif_ring() function reads the received CAN
frames from the chip, iterates over them and pushes them into the
network stack. Prepare that the iteration can be stopped if an old CAN
frame is detected. The actual code to detect old or incomplete frames
and abort will be added in the next patch.
Link: https://lore.kernel.org/all/BL3PR11MB64844C1C95CA3BDADAE4D8CCFBC99@BL3PR11MB6484.namprd11.prod.outlook.com
Reported-by: Stefan Althöfer <Stefan.Althoefer@janztec.com>
Closes: https://lore.kernel.org/all/FR0P281MB1966273C216630B120ABB6E197E89@FR0P281MB1966.DEUP281.PROD.OUTLOOK.COM
Tested-by: Stefan Althöfer <Stefan.Althoefer@janztec.com>
Tested-by: Thomas Kopp <thomas.kopp@microchip.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| 759822a3 | 22-Jan-2023 |
Marc Kleine-Budde <mkl@pengutronix.de> |
can: mcp251xfd: tef: update workaround for erratum DS80000789E 6 of mcp2518fd
[ Upstream commit 3a0a88fcbaf9e027ecca3fe8775be9700b4d6460 ]
This patch updates the workaround for a problem similar to
can: mcp251xfd: tef: update workaround for erratum DS80000789E 6 of mcp2518fd
[ Upstream commit 3a0a88fcbaf9e027ecca3fe8775be9700b4d6460 ]
This patch updates the workaround for a problem similar to erratum
DS80000789E 6 of the mcp2518fd, the other variants of the chip
family (mcp2517fd and mcp251863) are probably also affected.
Erratum DS80000789E 6 says "reading of the FIFOCI bits in the FIFOSTA
register for an RX FIFO may be corrupted". However observation shows
that this problem is not limited to RX FIFOs but also effects the TEF
FIFO.
In the bad case, the driver reads a too large head index. As the FIFO
is implemented as a ring buffer, this results in re-handling old CAN
transmit complete events.
Every transmit complete event contains with a sequence number that
equals to the sequence number of the corresponding TX request. This
way old TX complete events can be detected.
If the original driver detects a non matching sequence number, it
prints an info message and tries again later. As wrong sequence
numbers can be explained by the erratum DS80000789E 6, demote the info
message to debug level, streamline the code and update the comments.
Keep the behavior: If an old CAN TX complete event is detected, abort
the iteration and mark the number of valid CAN TX complete events as
processed in the chip by incrementing the FIFO's tail index.
Cc: Stefan Althöfer <Stefan.Althoefer@janztec.com>
Cc: Thomas Kopp <thomas.kopp@microchip.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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