From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Gustavo A. R. Silva" Subject: [PATCH] spi: bcm2835aux: use 64-bit arithmetic instead of 32-bit Date: Wed, 7 Feb 2018 10:00:02 -0600 Message-ID: <20180207160002.GA9292@embeddedgus> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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" To: Mark Brown , Eric Anholt , Stefan Wahren , Florian Fainelli , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.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