From nobody Sat Feb 7 20:38:50 2026 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 33354C4167E for ; Mon, 23 May 2022 17:53:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244099AbiEWRv4 (ORCPT ); Mon, 23 May 2022 13:51:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241457AbiEWR0q (ORCPT ); Mon, 23 May 2022 13:26:46 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73D49719D2; Mon, 23 May 2022 10:21:50 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9FE15B8120F; Mon, 23 May 2022 17:20:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B24DC3411C; Mon, 23 May 2022 17:20:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1653326416; bh=lhOmLS/R9QJKcENUCDPWK6y1PeRsDp5qBeu0TJ02EbQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fVAoOkt70QgklKaasB2A1J9x6BCrxXjdtWoQBDQdQzqq50eyU06DGCDop35Bv6qnV pHfcWRHUCOsjVxWErUXAUC/HxAFs1ElkoPdJhmtZox2iG+6zSQoEEZ3vXIKzJg6L/B 1ShI5JiNUOfxVjbEEFFeUBorIEug5TMrQHotWFQs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jarkko Nikula , Chee Hou Ong , Aman Kumar , Pallavi Kumari , Marc Kleine-Budde Subject: [PATCH 5.15 051/132] Revert "can: m_can: pci: use custom bit timings for Elkhart Lake" Date: Mon, 23 May 2022 19:04:20 +0200 Message-Id: <20220523165831.688100631@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220523165823.492309987@linuxfoundation.org> References: <20220523165823.492309987@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Jarkko Nikula commit 14ea4a470494528c7e88da5c4116c24eb027059f upstream. This reverts commit 0e8ffdf3b86dfd44b651f91b12fcae76c25c453b. Commit 0e8ffdf3b86d ("can: m_can: pci: use custom bit timings for Elkhart Lake") broke the test case using bitrate switching. | ip link set can0 up type can bitrate 500000 dbitrate 4000000 fd on | ip link set can1 up type can bitrate 500000 dbitrate 4000000 fd on | candump can0 & | cangen can1 -I 0x800 -L 64 -e -fb \ | -D 11223344deadbeef55667788feedf00daabbccdd44332211 -n 1 -v -v Above commit does everything correctly according to the datasheet. However datasheet wasn't correct. I got confirmation from hardware engineers that the actual CAN hardware on Intel Elkhart Lake is based on M_CAN version v3.2.0. Datasheet was mirroring values from an another specification which was based on earlier M_CAN version leading to wrong bit timings. Therefore revert the commit and switch back to common bit timings. Fixes: ea4c1787685d ("can: m_can: pci: use custom bit timings for Elkhart L= ake") Link: https://lore.kernel.org/all/20220512124144.536850-1-jarkko.nikula@lin= ux.intel.com Signed-off-by: Jarkko Nikula Reported-by: Chee Hou Ong Reported-by: Aman Kumar Reported-by: Pallavi Kumari Cc: # v5.16+ Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/m_can/m_can_pci.c | 48 +++------------------------------= ----- 1 file changed, 4 insertions(+), 44 deletions(-) --- a/drivers/net/can/m_can/m_can_pci.c +++ b/drivers/net/can/m_can/m_can_pci.c @@ -18,14 +18,9 @@ =20 #define M_CAN_PCI_MMIO_BAR 0 =20 +#define M_CAN_CLOCK_FREQ_EHL 200000000 #define CTL_CSR_INT_CTL_OFFSET 0x508 =20 -struct m_can_pci_config { - const struct can_bittiming_const *bit_timing; - const struct can_bittiming_const *data_timing; - unsigned int clock_freq; -}; - struct m_can_pci_priv { struct m_can_classdev cdev; =20 @@ -89,40 +84,9 @@ static struct m_can_ops m_can_pci_ops =3D .read_fifo =3D iomap_read_fifo, }; =20 -static const struct can_bittiming_const m_can_bittiming_const_ehl =3D { - .name =3D KBUILD_MODNAME, - .tseg1_min =3D 2, /* Time segment 1 =3D prop_seg + phase_seg1 */ - .tseg1_max =3D 64, - .tseg2_min =3D 1, /* Time segment 2 =3D phase_seg2 */ - .tseg2_max =3D 128, - .sjw_max =3D 128, - .brp_min =3D 1, - .brp_max =3D 512, - .brp_inc =3D 1, -}; - -static const struct can_bittiming_const m_can_data_bittiming_const_ehl =3D= { - .name =3D KBUILD_MODNAME, - .tseg1_min =3D 2, /* Time segment 1 =3D prop_seg + phase_seg1 */ - .tseg1_max =3D 16, - .tseg2_min =3D 1, /* Time segment 2 =3D phase_seg2 */ - .tseg2_max =3D 8, - .sjw_max =3D 4, - .brp_min =3D 1, - .brp_max =3D 32, - .brp_inc =3D 1, -}; - -static const struct m_can_pci_config m_can_pci_ehl =3D { - .bit_timing =3D &m_can_bittiming_const_ehl, - .data_timing =3D &m_can_data_bittiming_const_ehl, - .clock_freq =3D 200000000, -}; - static int m_can_pci_probe(struct pci_dev *pci, const struct pci_device_id= *id) { struct device *dev =3D &pci->dev; - const struct m_can_pci_config *cfg; struct m_can_classdev *mcan_class; struct m_can_pci_priv *priv; void __iomem *base; @@ -150,8 +114,6 @@ static int m_can_pci_probe(struct pci_de if (!mcan_class) return -ENOMEM; =20 - cfg =3D (const struct m_can_pci_config *)id->driver_data; - priv =3D cdev_to_priv(mcan_class); =20 priv->base =3D base; @@ -163,9 +125,7 @@ static int m_can_pci_probe(struct pci_de mcan_class->dev =3D &pci->dev; mcan_class->net->irq =3D pci_irq_vector(pci, 0); mcan_class->pm_clock_support =3D 1; - mcan_class->bit_timing =3D cfg->bit_timing; - mcan_class->data_timing =3D cfg->data_timing; - mcan_class->can.clock.freq =3D cfg->clock_freq; + mcan_class->can.clock.freq =3D id->driver_data; mcan_class->ops =3D &m_can_pci_ops; =20 pci_set_drvdata(pci, mcan_class); @@ -218,8 +178,8 @@ static SIMPLE_DEV_PM_OPS(m_can_pci_pm_op m_can_pci_suspend, m_can_pci_resume); =20 static const struct pci_device_id m_can_pci_id_table[] =3D { - { PCI_VDEVICE(INTEL, 0x4bc1), (kernel_ulong_t)&m_can_pci_ehl, }, - { PCI_VDEVICE(INTEL, 0x4bc2), (kernel_ulong_t)&m_can_pci_ehl, }, + { PCI_VDEVICE(INTEL, 0x4bc1), M_CAN_CLOCK_FREQ_EHL, }, + { PCI_VDEVICE(INTEL, 0x4bc2), M_CAN_CLOCK_FREQ_EHL, }, { } /* Terminating Entry */ }; MODULE_DEVICE_TABLE(pci, m_can_pci_id_table);