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authorFedor Ross <fedor.ross@ifm.com>2023-05-04 21:50:59 +0200
committerMarc Kleine-Budde <mkl@pengutronix.de>2023-07-17 19:54:51 +0200
commit9efa1a5407e81265ea502cab83be4de503decc49 (patch)
tree046baedb0e30c96b47d388aac14de30bc1c0b928 /drivers/net/can
parentdc050849d93f4c5d8a88dc6789668212b7785967 (diff)
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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>
Diffstat (limited to 'drivers/net/can')
-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c10
-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd.h1
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