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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 CAC87C4338F for ; Mon, 26 Jul 2021 16:12:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF0D560F5A for ; Mon, 26 Jul 2021 16:12:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233417AbhGZPcU (ORCPT ); Mon, 26 Jul 2021 11:32:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:45300 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231924AbhGZPaJ (ORCPT ); Mon, 26 Jul 2021 11:30:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C231260C40; Mon, 26 Jul 2021 16:10:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627315837; bh=Y3bM3GTuZNYz9q2tHbFG4CKXGoYbMRHhx0x9LQPAyMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=URfNzv4vzQH8qJL19YQte3Qru7IahG7l8Ct5BbTaHYvPAtoPM2L77egMU9zA4JvJ/ b18YfDgi0AbFybqdWcJdmtHhGKsW5+lOWMSnkI4pD8vYK0Z8cN/08bC5KDZha6bKQ7 PWgPDdcg5lcfvvjrWn3yEp1Tzt3ZMOtdzW+0b4wY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yoshitaka Ikeda , Mark Brown , Sasha Levin Subject: [PATCH 5.13 087/223] spi: spi-cadence-quadspi: Fix division by zero warning Date: Mon, 26 Jul 2021 17:37:59 +0200 Message-Id: <20210726153849.092335444@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153846.245305071@linuxfoundation.org> References: <20210726153846.245305071@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: stable@vger.kernel.org From: Yoshitaka Ikeda [ Upstream commit 55cef88bbf12f3bfbe5c2379a8868a034707e755 ] Fix below division by zero warning: - Added an if statement because buswidth can be zero, resulting in division by zero. - The modified code was based on another driver (atmel-quadspi). [ 0.795337] Division by zero in kernel. : [ 0.834051] [<807fd40c>] (__div0) from [<804e1acc>] (Ldiv0+0x8/0x10) [ 0.839097] [<805f0710>] (cqspi_exec_mem_op) from [<805edb4c>] (spi_mem_exec_op+0x3b0/0x3f8) Fixes: 7512eaf54190 ("spi: cadence-quadspi: Fix dummy cycle calculation when buswidth > 1") Signed-off-by: Yoshitaka Ikeda Link: https://lore.kernel.org/r/ed989af6-da88-4e0b-9ed8-126db6cad2e4@nskint.co.jp Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-cadence-quadspi.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 7a00346ff9b9..13d1f0ce618e 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -307,11 +307,13 @@ static unsigned int cqspi_calc_rdreg(struct cqspi_flash_pdata *f_pdata) static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op, bool dtr) { - unsigned int dummy_clk; + unsigned int dummy_clk = 0; - dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth); - if (dtr) - dummy_clk /= 2; + if (op->dummy.buswidth && op->dummy.nbytes) { + dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth); + if (dtr) + dummy_clk /= 2; + } return dummy_clk; } -- 2.30.2