From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 972FAC0015E for ; Tue, 25 Jul 2023 11:03:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233863AbjGYLDP (ORCPT ); Tue, 25 Jul 2023 07:03:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233940AbjGYLDC (ORCPT ); Tue, 25 Jul 2023 07:03:02 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DD653C04 for ; Tue, 25 Jul 2023 04:00:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C68666168F for ; Tue, 25 Jul 2023 10:59:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFA47C433C8; Tue, 25 Jul 2023 10:59:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690282776; bh=O0MYpKJAu6O2RZA8uyHT2fGeT/lXMDi55sq3TvleQ0c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PLg5Ye+1+PzWqogSt7O5/5BNVOALo08MJy3P1Cl/QYP96kknU2RLiq5suAMOyhdKd isU3AGJy1fhTIevnNoeCkG0gLmbkZBgka6M4sDX+ZLW21d6jLdMPBJBcsB/3ZSKkMR iw3r2dbdb1Ecgz2CLA/kvz0liSwSN8w2T1zeBNNQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Fedor Ross , Marek Vasut , Marc Kleine-Budde Subject: [PATCH 6.1 022/183] can: mcp251xfd: __mcp251xfd_chip_set_mode(): increase poll timeout Date: Tue, 25 Jul 2023 12:44:10 +0200 Message-ID: <20230725104508.692959275@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104507.756981058@linuxfoundation.org> References: <20230725104507.756981058@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Fedor Ross commit 9efa1a5407e81265ea502cab83be4de503decc49 upstream. 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 Signed-off-by: Marek Vasut 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 Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 10 ++++++++-- drivers/net/can/spi/mcp251xfd/mcp251xfd.h | 1 + 2 files changed, 9 insertions(+), 2 deletions(-) --- 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 m 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; --- 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_D #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