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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A1B9C606C1 for ; Mon, 8 Jul 2019 15:20:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFCF6216F4 for ; Mon, 8 Jul 2019 15:20:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599208; bh=2VdFkdk9SIaAdzepBOAW1EfUckj2mgK2DM94z7kTn2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UYTc2PGaqzCcIZ7zvHKN4n5GCzq6fgoACamQ9xrDsWRoN7VAhGUasJ50WvWhWqsUZ +jiw8rSsvu6ygXF9BNGDjY/xin07+40+BYYj2ZOJZ/OpgsPvhVyqV8J4CLtsIvDDvB 0AxY6nrIuQ1E8mNV1pTmSBT6RiKcqSDsvFF2Q1Lw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387565AbfGHPUD (ORCPT ); Mon, 8 Jul 2019 11:20:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:43836 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729037AbfGHPT2 (ORCPT ); Mon, 8 Jul 2019 11:19:28 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 672F6216E3; Mon, 8 Jul 2019 15:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599167; bh=2VdFkdk9SIaAdzepBOAW1EfUckj2mgK2DM94z7kTn2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=G+oQ6GiDxlOVcjsMYGss0P7+YM2q63aMt5lSHdcvxAQ/PQD7iTZ9qFYw65hPqw4/w gu2HzWbPtCLKTCD6NQ4KK/rMokJ9nvvcCQd1QGtHnqqtC2xfR+IwI36mXHHGc5agsr YDyEJ+0xd72EElih9MUrSFjygHxwOvemsaADVtlE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joakim Zhang , Dong Aisheng , Marc Kleine-Budde Subject: [PATCH 4.9 027/102] can: flexcan: fix timeout when set small bitrate Date: Mon, 8 Jul 2019 17:12:20 +0200 Message-Id: <20190708150527.701988108@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150525.973820964@linuxfoundation.org> References: <20190708150525.973820964@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joakim Zhang commit 247e5356a709eb49a0d95ff2a7f07dac05c8252c upstream. Current we can meet timeout issue when setting a small bitrate like 10000 as follows on i.MX6UL EVK board (ipg clock = 66MHZ, per clock = 30MHZ): | root@imx6ul7d:~# ip link set can0 up type can bitrate 10000 A link change request failed with some changes committed already. Interface can0 may have been left with an inconsistent configuration, please check. | RTNETLINK answers: Connection timed out It is caused by calling of flexcan_chip_unfreeze() timeout. Originally the code is using usleep_range(10, 20) for unfreeze operation, but the patch (8badd65 can: flexcan: avoid calling usleep_range from interrupt context) changed it into udelay(10) which is only a half delay of before, there're also some other delay changes. After double to FLEXCAN_TIMEOUT_US to 100 can fix the issue. Meanwhile, Rasmus Villemoes reported that even with a timeout of 100, flexcan_probe() fails on the MPC8309, which requires a value of at least 140 to work reliably. 250 works for everyone. Signed-off-by: Joakim Zhang Reviewed-by: Dong Aisheng Cc: linux-stable Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/flexcan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -171,7 +171,7 @@ #define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16) #define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff) -#define FLEXCAN_TIMEOUT_US (50) +#define FLEXCAN_TIMEOUT_US (250) /* FLEXCAN hardware feature flags *