Hi Julia, On Wed, 8 Sep 2010 07:58:45 +0200 (CEST), Julia Lawall wrote: > From: Julia Lawall <julia@xxxxxxx> > > In each case, the function has an unsigned return type, but returns a > negative constant to indicate an error condition. The result of calling > the function is always stored in a variable of type (signed) int, and thus > unsigned can be dropped from the return type. > > A sematic match that finds this problem is as follows: > (http://coccinelle.lip6.fr/) > > // <smpl> > @exists@ > identifier f; > constant C; > @@ > > unsigned f(...) > { <+... > * return -C; > ...+> } > // </smpl> > > Signed-off-by: Julia Lawall <julia@xxxxxxx> > > --- > drivers/i2c/busses/i2c-amd8111.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-amd8111.c b/drivers/i2c/busses/i2c-amd8111.c > index af1e5e2..02a3726 100644 > --- a/drivers/i2c/busses/i2c-amd8111.c > +++ b/drivers/i2c/busses/i2c-amd8111.c > @@ -69,7 +69,7 @@ static struct pci_driver amd8111_driver; > * ACPI 2.0 chapter 13 access of registers of the EC > */ > > -static unsigned int amd_ec_wait_write(struct amd_smbus *smbus) > +static int amd_ec_wait_write(struct amd_smbus *smbus) > { > int timeout = 500; > > @@ -85,7 +85,7 @@ static unsigned int amd_ec_wait_write(struct amd_smbus *smbus) > return 0; > } > > -static unsigned int amd_ec_wait_read(struct amd_smbus *smbus) > +static int amd_ec_wait_read(struct amd_smbus *smbus) > { > int timeout = 500; > > Thanks for reporting. Unfortunately the fix above is incomplete. amd_ec_wait_write() and amd_ec_wait_read() are called by amd_ec_read() and amd_ec_write(), which will now attempt to return negative error codes as unsigned ints. So amd_ec_read() and amd_ec_write() must have their return type fixed too. Note that the driver code never checks for errors returned by amd_ec_read() or amd_ec_write() anyway, so the fix alone is a no-op. A real fix would have to also update the caller sites to properly deal with errors if then happen. -- Jean Delvare -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
