From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 5.4 07/58] i2c: altera: Fix potential integer overflow Date: Thu, 5 Mar 2020 12:13:28 -0500 Message-ID: <20200305171420.29595-7-sashal@kernel.org> References: <20200305171420.29595-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from mail.kernel.org ([198.145.29.99]:40644 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727689AbgCEROa (ORCPT ); Thu, 5 Mar 2020 12:14:30 -0500 In-Reply-To: <20200305171420.29595-1-sashal@kernel.org> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Gustavo A. R. Silva" , David Laight , Thor Thayer , Wolfram Sang , Sasha Levin , linux-i2c@vger.kernel.org From: "Gustavo A. R. Silva" [ Upstream commit 54498e8070e19e74498a72c7331348143e7e1f8c ] Factor out 100 from the equation and do 32-bit arithmetic (3 * clk_mhz / 10) instead of 64-bit. Notice that clk_mhz is MHz, so the multiplication will never wrap 32 bits and there is no need for div_u64(). Addresses-Coverity: 1458369 ("Unintentional integer overflow") Fixes: 0560ad576268 ("i2c: altera: Add Altera I2C Controller driver") Suggested-by: David Laight Signed-off-by: Gustavo A. R. Silva Reviewed-by: Thor Thayer Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-altera.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c index 5255d3755411b..1de23b4f3809c 100644 --- a/drivers/i2c/busses/i2c-altera.c +++ b/drivers/i2c/busses/i2c-altera.c @@ -171,7 +171,7 @@ static void altr_i2c_init(struct altr_i2c_dev *idev) /* SCL Low Time */ writel(t_low, idev->base + ALTR_I2C_SCL_LOW); /* SDA Hold Time, 300ns */ - writel(div_u64(300 * clk_mhz, 1000), idev->base + ALTR_I2C_SDA_HOLD); + writel(3 * clk_mhz / 10, idev->base + ALTR_I2C_SDA_HOLD); /* Mask all master interrupt bits */ altr_i2c_int_enable(idev, ALTR_I2C_ALL_IRQ, false); -- 2.20.1