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=-9.8 required=3.0 tests=BAYES_00,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 F3C47C2D0A3 for ; Tue, 3 Nov 2020 20:46:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2426223FD for ; Tue, 3 Nov 2020 20:46:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436361; bh=FytFa8TWDqxC9E6EocZFRBk3FNc7lYI4RPDDGt0dgjQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gPw3mKtKXcmYNqHjBkll6rQmzCfDaa2xZl+27Xml/3l/LQSoEO/8+1UOubHva3MKz qXnULtFVRfY7tdtphGa9pNuYhxGqAoOiAZBrjpuY/ME2P+RoyKrfGYLA43g64CU6ys EGSx98N+DFC1GpOCcbrqsmdPTOTLxYOO3bJrNdfU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731126AbgKCUqA (ORCPT ); Tue, 3 Nov 2020 15:46:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:34792 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731111AbgKCUp6 (ORCPT ); Tue, 3 Nov 2020 15:45:58 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 077D1223EA; Tue, 3 Nov 2020 20:45:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604436357; bh=FytFa8TWDqxC9E6EocZFRBk3FNc7lYI4RPDDGt0dgjQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jSzlTemOXXaSjHQ4ZTnKBbgJuFg7GBsdq3d1U7F9MyKFLRdZ+88r7SLekGj7jaNem 5iGpCpzDO32t0xz0mfaGrSxUVx1AnIxg/Wp9Uc2zvR7JBeZBRrYOKPExeusC7KZ50q XMLlEM5UW0WszaWlM7ULFJweuXuDLFeDizobqKU0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Fuzzey Subject: [PATCH 5.9 214/391] w1: mxc_w1: Fix timeout resolution problem leading to bus error Date: Tue, 3 Nov 2020 21:34:25 +0100 Message-Id: <20201103203401.374038704@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201103203348.153465465@linuxfoundation.org> References: <20201103203348.153465465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Martin Fuzzey commit c9723750a699c3bd465493ac2be8992b72ccb105 upstream. On my platform (i.MX53) bus access sometimes fails with w1_search: max_slave_count 64 reached, will continue next search. The reason is the use of jiffies to implement a 200us timeout in mxc_w1_ds2_touch_bit(). On some platforms the jiffies timer resolution is insufficient for this. Fix by replacing jiffies by ktime_get(). For consistency apply the same change to the other use of jiffies in mxc_w1_ds2_reset_bus(). Fixes: f80b2581a706 ("w1: mxc_w1: Optimize mxc_w1_ds2_touch_bit()") Cc: stable Signed-off-by: Martin Fuzzey Link: https://lore.kernel.org/r/1601455030-6607-1-git-send-email-martin.fuzzey@flowbird.group Signed-off-by: Greg Kroah-Hartman --- drivers/w1/masters/mxc_w1.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/drivers/w1/masters/mxc_w1.c +++ b/drivers/w1/masters/mxc_w1.c @@ -7,7 +7,7 @@ #include #include #include -#include +#include #include #include #include @@ -40,12 +40,12 @@ struct mxc_w1_device { static u8 mxc_w1_ds2_reset_bus(void *data) { struct mxc_w1_device *dev = data; - unsigned long timeout; + ktime_t timeout; writeb(MXC_W1_CONTROL_RPP, dev->regs + MXC_W1_CONTROL); /* Wait for reset sequence 511+512us, use 1500us for sure */ - timeout = jiffies + usecs_to_jiffies(1500); + timeout = ktime_add_us(ktime_get(), 1500); udelay(511 + 512); @@ -55,7 +55,7 @@ static u8 mxc_w1_ds2_reset_bus(void *dat /* PST bit is valid after the RPP bit is self-cleared */ if (!(ctrl & MXC_W1_CONTROL_RPP)) return !(ctrl & MXC_W1_CONTROL_PST); - } while (time_is_after_jiffies(timeout)); + } while (ktime_before(ktime_get(), timeout)); return 1; } @@ -68,12 +68,12 @@ static u8 mxc_w1_ds2_reset_bus(void *dat static u8 mxc_w1_ds2_touch_bit(void *data, u8 bit) { struct mxc_w1_device *dev = data; - unsigned long timeout; + ktime_t timeout; writeb(MXC_W1_CONTROL_WR(bit), dev->regs + MXC_W1_CONTROL); /* Wait for read/write bit (60us, Max 120us), use 200us for sure */ - timeout = jiffies + usecs_to_jiffies(200); + timeout = ktime_add_us(ktime_get(), 200); udelay(60); @@ -83,7 +83,7 @@ static u8 mxc_w1_ds2_touch_bit(void *dat /* RDST bit is valid after the WR1/RD bit is self-cleared */ if (!(ctrl & MXC_W1_CONTROL_WR(bit))) return !!(ctrl & MXC_W1_CONTROL_RDST); - } while (time_is_after_jiffies(timeout)); + } while (ktime_before(ktime_get(), timeout)); return 0; }