The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 9efa1a5407e81265ea502cab83be4de503decc49 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023072312-thaw-tug-693d@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:

9efa1a5407e8 ("can: mcp251xfd: __mcp251xfd_chip_set_mode(): increase poll timeout") c9e6b80dfd48 ("can: mcp251xfd: update macros describing ring, FIFO and RAM layout") 0a1f2e6502a1 ("can: mcp251xfd: ring: prepare support for runtime configurable RX/TX ring parameters") aada74220f00 ("can: mcp251xfd: mcp251xfd_priv: introduce macros specifying the number of supported TEF/RX/TX rings") 62713f0d9a38 ("can: mcp251xfd: ring: change order of TX and RX FIFOs") 617283b9c4db ("can: mcp251xfd: ring: prepare to change order of TX and RX FIFOs") d2d5397fcae1 ("can: mcp251xfd: mcp251xfd_ring_init(): split ring_init into separate functions") c912f19ee382 ("can: mcp251xfd: introduce struct mcp251xfd_tx_ring::nr and ::fifo_nr and make use of it") 2a68dd8663ea ("can: mcp251xfd: add support for internal PLL") e39ea1360ca7 ("can: mcp251xfd: mcp251xfd_chip_clock_init(): prepare for PLL support, wait for OSC ready") a10fd91e42e8 ("can: mcp251xfd: __mcp251xfd_chip_set_mode(): prepare for PLL support: improve error handling and diagnostics") 14193ea2bfee ("can: mcp251xfd: mcp251xfd_chip_timestamp_init(): factor out into separate function") 1ba3690fa2c6 ("can: mcp251xfd: mcp251xfd_chip_sleep(): introduce function to bring chip into sleep mode") 3044a4f271d2 ("can: mcp251xfd: introduce and make use of mcp251xfd_is_fd_mode()") 55bc37c85587 ("can: mcp251xfd: move ring init into separate function") 335c818c5a7a ("can: mcp251xfd: move chip FIFO init into separate file") 1e846c7aeb06 ("can: mcp251xfd: move TEF handling into separate file") 319fdbc9433c ("can: mcp251xfd: move RX handling into separate file") cae9071bc5ea ("can: mcp251xfd: mcp251xfd.h: sort function prototypes") 99e7cc3b3f85 ("can: mcp251xfd: mcp251xfd_tef_obj_read(): fix typo in error message")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9efa1a5407e81265ea502cab83be4de503decc49 Mon Sep 17 00:00:00 2001 From: Fedor Ross fedor.ross@ifm.com Date: Thu, 4 May 2023 21:50:59 +0200 Subject: [PATCH] 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-... Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de

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