From fa115486bfbfc5a32e4cec060fdcd94d2fa9cccd Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Tue, 11 Feb 2020 08:47:04 -0600 Subject: [PATCH] i2c: altera: Fix potential integer overflow BugLink: https://bugs.launchpad.net/bugs/1866333 commit 54498e8070e19e74498a72c7331348143e7e1f8c upstream. 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: Greg Kroah-Hartman Signed-off-by: Paolo Pisati --- 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 5255d3755411..1de23b4f3809 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); -- 2.39.5