On Mon, 1 Feb 2010 09:51:42 +0000, d binderman wrote:
>
>
> Hello there,
>
> I just ran the sourceforge tool cppcheck over the source code of the
> new Linux kernel 2.6.33-rc6
>
> It said
>
> [./i2c/busses/i2c-highlander.c:284]: (style) Warning - using char variable in bit operation
>
> The source code is
>
> static int highlander_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
> unsigned short flags, char read_write,
> u8 command, int size,
> union i2c_smbus_data *data)
> {
> struct highlander_i2c_dev *dev = i2c_get_adapdata(adap);
> int read = read_write & I2C_SMBUS_READ;
>
> In C, chars can be signed or unsigned, so the value written into
> local variable read by sign extension is not certain.
>
> Suggest new code
>
> static int highlander_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
> unsigned short flags, char read_write,
> u8 command, int size,
> union i2c_smbus_data *data)
> {
> struct highlander_i2c_dev *dev = i2c_get_adapdata(adap);
> int read = ((unsigned char) read_write) & I2C_SMBUS_READ;
read_write can only have value 0 or 1, so we don't care if chars are
signed or not. That being said, the code above looks odd, the value of
read_write can be used in the code directly without using an
intermediate variable:
iowrite16((addr << 1) | read_write, dev->base + SMSMADR);
This would solve your warning issue and make the code more simple too.
--
Jean Delvare
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