| Message ID | 1442311867-60185-1-git-send-email-andriy.shevchenko@linux.intel.com |
|---|---|
| State | Superseded |
| Headers | show |
On 15/09/15 12:11, EXT Andy Shevchenko wrote: > There is a warning when compiling i2c-core.c > drivers/i2c/i2c-core.c:2561:36: warning: dubious: x | !y > > Fix it by using ternary operator. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> > --- > drivers/i2c/i2c-core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index 3a4c54e..d13a8a0 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -2591,7 +2591,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) > static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) > { > /* The address will be sent first */ > - u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); > + u8 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) ? 1 : 0); > pec = i2c_smbus_pec(pec, &addr, 1); > > /* The data buffer follows */
Hello Andy, On 15.09.2015 13:11, Andy Shevchenko wrote: > There is a warning when compiling i2c-core.c > drivers/i2c/i2c-core.c:2561:36: warning: dubious: x | !y > > Fix it by using ternary operator. > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > --- > drivers/i2c/i2c-core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > index 3a4c54e..d13a8a0 100644 > --- a/drivers/i2c/i2c-core.c > +++ b/drivers/i2c/i2c-core.c > @@ -2591,7 +2591,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) > static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) > { > /* The address will be sent first */ > - u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); > + u8 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) ? 1 : 0); > pec = i2c_smbus_pec(pec, &addr, 1); > > /* The data buffer follows */ > I2C_M_RD is defined as 1, probably (msg->flags & I2C_M_RD) is good enough here. -- With best wishes, Vladimir -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 2015-09-15 at 14:25 +0300, Vladimir Zapolskiy wrote: > Hello Andy, > > On 15.09.2015 13:11, Andy Shevchenko wrote: > > There is a warning when compiling i2c-core.c > > drivers/i2c/i2c-core.c:2561:36: warning: dubious: x | !y > > > > Fix it by using ternary operator. > > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > > --- > > drivers/i2c/i2c-core.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c > > index 3a4c54e..d13a8a0 100644 > > --- a/drivers/i2c/i2c-core.c > > +++ b/drivers/i2c/i2c-core.c > > @@ -2591,7 +2591,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t > > count) > > static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) > > { > > /* The address will be sent first */ > > - u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); > > + u8 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) ? 1 > > : 0); > > pec = i2c_smbus_pec(pec, &addr, 1); > > > > /* The data buffer follows */ > > > > I2C_M_RD is defined as 1, probably (msg->flags & I2C_M_RD) is good > enough here. Today is 1, tomorrow is 0x80, so, I would stay as I put in the initial fix. > > -- > With best wishes, > Vladimir
On 15.09.2015 15:06, Andy Shevchenko wrote: > On Tue, 2015-09-15 at 14:25 +0300, Vladimir Zapolskiy wrote: >> Hello Andy, >> >> On 15.09.2015 13:11, Andy Shevchenko wrote: >>> There is a warning when compiling i2c-core.c >>> drivers/i2c/i2c-core.c:2561:36: warning: dubious: x | !y >>> >>> Fix it by using ternary operator. >>> >>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> >>> --- >>> drivers/i2c/i2c-core.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c >>> index 3a4c54e..d13a8a0 100644 >>> --- a/drivers/i2c/i2c-core.c >>> +++ b/drivers/i2c/i2c-core.c >>> @@ -2591,7 +2591,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t >>> count) >>> static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) >>> { >>> /* The address will be sent first */ >>> - u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); >>> + u8 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) ? 1 >>> : 0); >>> pec = i2c_smbus_pec(pec, &addr, 1); >>> >>> /* The data buffer follows */ >>> >> >> I2C_M_RD is defined as 1, probably (msg->flags & I2C_M_RD) is good >> enough here. > > Today is 1, tomorrow is 0x80, so, I would stay as I put in the initial > fix. I believe I2C_M_RD will never get any other value than 1, since this value is deliberately set to 1 and it is in active use by userspace applications for years, nobody intends to break ABI tomorrow. -- With best wishes, Vladimir -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> >> I2C_M_RD is defined as 1, probably (msg->flags & I2C_M_RD) is good > >> enough here. > > > > Today is 1, tomorrow is 0x80, so, I would stay as I put in the initial > > fix. > > I believe I2C_M_RD will never get any other value than 1, since this > value is deliberately set to 1 and it is in active use by userspace > applications for years, nobody intends to break ABI tomorrow. I agree. That is one thing that permanently slips through the cracks, but I wanted to add a comment saying the I2C_M_RD is guaranteed to be 1 and then simplify the drivers. Maybe I should start with the comment right now...
On Tue, 2015-09-15 at 15:00 +0200, Wolfram Sang wrote: > > > > > > I2C_M_RD is defined as 1, probably (msg->flags & I2C_M_RD) is > > > > good > > > > enough here. > > > > > > Today is 1, tomorrow is 0x80, so, I would stay as I put in the > > > initial > > > fix. > > > > I believe I2C_M_RD will never get any other value than 1, since > > this > > value is deliberately set to 1 and it is in active use by userspace > > applications for years, nobody intends to break ABI tomorrow. > > I agree. That is one thing that permanently slips through the cracks, > but I wanted to add a comment saying the I2C_M_RD is guaranteed to be > 1 > and then simplify the drivers. Yes, with comment on I2C_M_RD we may drop wrong assumptions. > > Maybe I should start with the comment right now... Please, update my patch accordingly, or ping me to update it. Right now busy with something else.
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 3a4c54e..d13a8a0 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -2591,7 +2591,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) { /* The address will be sent first */ - u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); + u8 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) ? 1 : 0); pec = i2c_smbus_pec(pec, &addr, 1); /* The data buffer follows */
There is a warning when compiling i2c-core.c drivers/i2c/i2c-core.c:2561:36: warning: dubious: x | !y Fix it by using ternary operator. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/i2c/i2c-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)