diff options
| author | Fedor Ross <fedor.ross@ifm.com> | 2023-05-04 21:50:59 +0200 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2023-07-17 19:54:51 +0200 |
| commit | 9efa1a5407e81265ea502cab83be4de503decc49 (patch) | |
| tree | 046baedb0e30c96b47d388aac14de30bc1c0b928 | |
| parent | dc050849d93f4c5d8a88dc6789668212b7785967 (diff) | |
can: mcp251xfd: __mcp251xfd_chip_set_mode(): increase poll timeout
The mcp251xfd controller needs an idle bus to enter 'Normal CAN 2.0
mode' or . The maximum length of a CAN frame is 736 bits (64 data
bytes, CAN-FD, EFF mode, worst case bit stuffing and interframe
spacing). For low bit rates like 10 kbit/s the arbitrarily chosen
MCP251XFD_POLL_TIMEOUT_US of 1 ms is too small.
Otherwise during polling for the CAN controller to enter 'Normal CAN
2.0 mode' the timeout limit is exceeded and the configuration fails
with:
| $ ip link set dev can1 up type can bitrate 10000
| [ 731.911072] mcp251xfd spi2.1 can1: Controller failed to enter mode CAN 2.0 Mode (6) and stays in Configuration Mode (4) (con=0x068b0760, osc=0x00000468).
| [ 731.927192] mcp251xfd spi2.1 can1: CRC read error at address 0x0e0c (length=4, data=00 00 00 00, CRC=0x0000) retrying.
| [ 731.938101] A link change request failed with some changes committed already. Interface can1 may have been left with an inconsistent configuration, please check.
| RTNETLINK answers: Connection timed out
Make MCP251XFD_POLL_TIMEOUT_US timeout calculation dynamic. Use
maximum of 1ms and bit time of 1 full 64 data bytes CAN-FD frame in
EFF mode, worst case bit stuffing and interframe spacing at the
current bit rate.
For easier backporting define the macro MCP251XFD_FRAME_LEN_MAX_BITS
that holds the max frame length in bits, which is 736. This can be
replaced by can_frame_bits(true, true, true, true, CANFD_MAX_DLEN) in
a cleanup patch later.
Fixes: 55e5b97f003e8 ("can: mcp25xxfd: add driver for Microchip MCP25xxFD SPI CAN")
Signed-off-by: Fedor Ross <fedor.ross@ifm.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20230717-mcp251xfd-fix-increase-poll-timeout-v5-1-06600f34c684@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 10 | ||||
| -rw-r--r-- | drivers/net/can/spi/mcp251xfd/mcp251xfd.h | 1 |
2 files changed, 9 insertions, 2 deletions
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index 68df6d4641b5..eebf967f4711 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c @@ -227,6 +227,8 @@ static int __mcp251xfd_chip_set_mode(const struct mcp251xfd_priv *priv, const u8 mode_req, bool nowait) { + const struct can_bittiming *bt = &priv->can.bittiming; + unsigned long timeout_us = MCP251XFD_POLL_TIMEOUT_US; u32 con = 0, con_reqop, osc = 0; u8 mode; int err; @@ -246,12 +248,16 @@ __mcp251xfd_chip_set_mode(const struct mcp251xfd_priv *priv, if (mode_req == MCP251XFD_REG_CON_MODE_SLEEP || nowait) return 0; + if (bt->bitrate) + timeout_us = max_t(unsigned long, timeout_us, + MCP251XFD_FRAME_LEN_MAX_BITS * USEC_PER_SEC / + bt->bitrate); + err = regmap_read_poll_timeout(priv->map_reg, MCP251XFD_REG_CON, con, !mcp251xfd_reg_invalid(con) && FIELD_GET(MCP251XFD_REG_CON_OPMOD_MASK, con) == mode_req, - MCP251XFD_POLL_SLEEP_US, - MCP251XFD_POLL_TIMEOUT_US); + MCP251XFD_POLL_SLEEP_US, timeout_us); if (err != -ETIMEDOUT && err != -EBADMSG) return err; diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h index 7024ff0cc2c0..24510b3b8020 100644 --- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h @@ -387,6 +387,7 @@ static_assert(MCP251XFD_TIMESTAMP_WORK_DELAY_SEC < #define MCP251XFD_OSC_STAB_TIMEOUT_US (10 * MCP251XFD_OSC_STAB_SLEEP_US) #define MCP251XFD_POLL_SLEEP_US (10) #define MCP251XFD_POLL_TIMEOUT_US (USEC_PER_MSEC) +#define MCP251XFD_FRAME_LEN_MAX_BITS (736) /* Misc */ #define MCP251XFD_NAPI_WEIGHT 32 |