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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-11 17:47:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-05 18:42:19 +0300 |
| commit | 4bd4758487bcbe3678c47c2daffa7b5988da6994 (patch) | |
| tree | 90cf9d36b994a1401f3e0f51d6ec46cdbba327cc /drivers/i2c | |
| parent | 07a8e34251a22755c0a3f9ea8a173b5d30440811 (diff) | |
| download | linux-4bd4758487bcbe3678c47c2daffa7b5988da6994.tar.xz | |
i2c: altera: Fix potential integer overflow
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 <David.Laight@ACULAB.COM>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-altera.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c index f5e1941e65b5..a1cdcfc74acf 100644 --- a/drivers/i2c/busses/i2c-altera.c +++ b/drivers/i2c/busses/i2c-altera.c @@ -182,7 +182,7 @@ 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); |