From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754481AbeBGQAI (ORCPT ); Wed, 7 Feb 2018 11:00:08 -0500 Received: from gateway31.websitewelcome.com ([192.185.144.219]:44233 "EHLO gateway31.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754347AbeBGQAG (ORCPT ); Wed, 7 Feb 2018 11:00:06 -0500 Date: Wed, 7 Feb 2018 10:00:02 -0600 From: "Gustavo A. R. Silva" To: Mark Brown , Eric Anholt , Stefan Wahren , Florian Fainelli , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com Cc: linux-spi@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] spi: bcm2835aux: use 64-bit arithmetic instead of 32-bit Message-ID: <20180207160002.GA9292@embeddedgus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.175.4.238 X-Source-L: No X-Exim-ID: 1ejS8h-0044mw-L1 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.175.4.238]:60150 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 11 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add suffix ULL to constant 9 in order to give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type unsigned long long (64 bits, unsigned). The expression tfr->len * 9 * 1000000 is currently being evaluated using 32-bit arithmetic. Addresses-Coverity-ID: 1339619 Signed-off-by: Gustavo A. R. Silva --- drivers/spi/spi-bcm2835aux.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c index 7428091..a768c23 100644 --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -363,7 +363,7 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master, * chunk getting transferred - in our case the chunk size * is 3 bytes, so we approximate this by 9 bits/byte */ - xfer_time_us = tfr->len * 9 * 1000000; + xfer_time_us = tfr->len * 9ULL * 1000000; do_div(xfer_time_us, spi_used_hz); /* run in polling mode for short transfers */ -- 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: gustavo@embeddedor.com (Gustavo A. R. Silva) Date: Wed, 7 Feb 2018 10:00:02 -0600 Subject: [PATCH] spi: bcm2835aux: use 64-bit arithmetic instead of 32-bit Message-ID: <20180207160002.GA9292@embeddedgus> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Add suffix ULL to constant 9 in order to give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type unsigned long long (64 bits, unsigned). The expression tfr->len * 9 * 1000000 is currently being evaluated using 32-bit arithmetic. Addresses-Coverity-ID: 1339619 Signed-off-by: Gustavo A. R. Silva --- drivers/spi/spi-bcm2835aux.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c index 7428091..a768c23 100644 --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -363,7 +363,7 @@ static int bcm2835aux_spi_transfer_one(struct spi_master *master, * chunk getting transferred - in our case the chunk size * is 3 bytes, so we approximate this by 9 bits/byte */ - xfer_time_us = tfr->len * 9 * 1000000; + xfer_time_us = tfr->len * 9ULL * 1000000; do_div(xfer_time_us, spi_used_hz); /* run in polling mode for short transfers */ -- 2.7.4