Bitwise OR(|) operation with 0 always yield same result.
It fixes dubious x | !y sparse warning.
Signed-off-by: Harsh Jain <[email protected]>
---
drivers/staging/kpc2000/kpc2000_i2c.c | 16 +---------------
1 file changed, 1 insertion(+), 15 deletions(-)
diff --git a/drivers/staging/kpc2000/kpc2000_i2c.c b/drivers/staging/kpc2000/kpc2000_i2c.c
index b108da4..5f027d7c 100644
--- a/drivers/staging/kpc2000/kpc2000_i2c.c
+++ b/drivers/staging/kpc2000/kpc2000_i2c.c
@@ -536,29 +536,15 @@ static u32 i801_func(struct i2c_adapter *adapter)
u32 f =
I2C_FUNC_I2C | /* 0x00000001 (I enabled this one) */
- !I2C_FUNC_10BIT_ADDR | /* 0x00000002 */
- !I2C_FUNC_PROTOCOL_MANGLING | /* 0x00000004 */
((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) | /* 0x00000008 */
- !I2C_FUNC_SMBUS_BLOCK_PROC_CALL | /* 0x00008000 */
I2C_FUNC_SMBUS_QUICK | /* 0x00010000 */
- !I2C_FUNC_SMBUS_READ_BYTE | /* 0x00020000 */
- !I2C_FUNC_SMBUS_WRITE_BYTE | /* 0x00040000 */
- !I2C_FUNC_SMBUS_READ_BYTE_DATA | /* 0x00080000 */
- !I2C_FUNC_SMBUS_WRITE_BYTE_DATA | /* 0x00100000 */
- !I2C_FUNC_SMBUS_READ_WORD_DATA | /* 0x00200000 */
- !I2C_FUNC_SMBUS_WRITE_WORD_DATA | /* 0x00400000 */
- !I2C_FUNC_SMBUS_PROC_CALL | /* 0x00800000 */
- !I2C_FUNC_SMBUS_READ_BLOCK_DATA | /* 0x01000000 */
- !I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | /* 0x02000000 */
((priv->features & FEATURE_I2C_BLOCK_READ) ? I2C_FUNC_SMBUS_READ_I2C_BLOCK : 0) | /* 0x04000000 */
I2C_FUNC_SMBUS_WRITE_I2C_BLOCK | /* 0x08000000 */
I2C_FUNC_SMBUS_BYTE | /* _READ_BYTE _WRITE_BYTE */
I2C_FUNC_SMBUS_BYTE_DATA | /* _READ_BYTE_DATA _WRITE_BYTE_DATA */
I2C_FUNC_SMBUS_WORD_DATA | /* _READ_WORD_DATA _WRITE_WORD_DATA */
- I2C_FUNC_SMBUS_BLOCK_DATA | /* _READ_BLOCK_DATA _WRITE_BLOCK_DATA */
- !I2C_FUNC_SMBUS_I2C_BLOCK | /* _READ_I2C_BLOCK _WRITE_I2C_BLOCK */
- !I2C_FUNC_SMBUS_EMUL; /* _QUICK _BYTE _BYTE_DATA _WORD_DATA _PROC_CALL _WRITE_BLOCK_DATA _I2C_BLOCK _PEC */
+ I2C_FUNC_SMBUS_BLOCK_DATA; /* _READ_BLOCK_DATA _WRITE_BLOCK_DATA */
return f;
}
--
2.7.4
>-----Original Message-----
>From: devel <[email protected]> On Behalf Of Greg KH
>Sent: Thursday, August 01, 2019 11:35 AM
>To: Harsh Jain <[email protected]>
>Cc: [email protected]; [email protected]
>Subject: Re: [PATCH] staging:kpc2000:Fix dubious x | !y sparse warning
>
>On Thu, Aug 01, 2019 at 12:06:06AM +0530, Harsh Jain wrote:
>> Bitwise OR(|) operation with 0 always yield same result.
>> It fixes dubious x | !y sparse warning.
>>
>> Signed-off-by: Harsh Jain <[email protected]>
>> ---
>> drivers/staging/kpc2000/kpc2000_i2c.c | 16 +---------------
>> 1 file changed, 1 insertion(+), 15 deletions(-)
>>
>> diff --git a/drivers/staging/kpc2000/kpc2000_i2c.c b/drivers/staging/kpc2000/kpc2000_i2c.c
>> index b108da4..5f027d7c 100644
>> --- a/drivers/staging/kpc2000/kpc2000_i2c.c
>> +++ b/drivers/staging/kpc2000/kpc2000_i2c.c
>> @@ -536,29 +536,15 @@ static u32 i801_func(struct i2c_adapter *adapter)
>>
>> u32 f =
>> I2C_FUNC_I2C | /* 0x00000001 (I enabled this one) */
>> - !I2C_FUNC_10BIT_ADDR | /* 0x00000002 */
>> - !I2C_FUNC_PROTOCOL_MANGLING | /* 0x00000004 */
>> ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) | /* 0x00000008 */
>> - !I2C_FUNC_SMBUS_BLOCK_PROC_CALL | /* 0x00008000 */
>> I2C_FUNC_SMBUS_QUICK | /* 0x00010000 */
>> - !I2C_FUNC_SMBUS_READ_BYTE | /* 0x00020000 */
>> - !I2C_FUNC_SMBUS_WRITE_BYTE | /* 0x00040000 */
>> - !I2C_FUNC_SMBUS_READ_BYTE_DATA | /* 0x00080000 */
>> - !I2C_FUNC_SMBUS_WRITE_BYTE_DATA | /* 0x00100000 */
>> - !I2C_FUNC_SMBUS_READ_WORD_DATA | /* 0x00200000 */
>> - !I2C_FUNC_SMBUS_WRITE_WORD_DATA | /* 0x00400000 */
>> - !I2C_FUNC_SMBUS_PROC_CALL | /* 0x00800000 */
>> - !I2C_FUNC_SMBUS_READ_BLOCK_DATA | /* 0x01000000 */
>> - !I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | /* 0x02000000 */
>
>This is ok, it is showing you that these bits are explicitly being not
>set. Which is good, now you can go through the list and see that all
>are accounted for.
>
>So I think this should stay as-is, thanks.
I was going to say the same thing, but I didn't know what the kernel style guideline was.
Would Linus prefer this style or would commenting them out be preferred?
Seems like the sparse warnings means the current style is not acceptable?
On Thu, Aug 01, 2019 at 07:22:13PM +0000, Matt Sickler wrote:
> >-----Original Message-----
> >From: devel <[email protected]> On Behalf Of Greg KH
> >Sent: Thursday, August 01, 2019 11:35 AM
> >To: Harsh Jain <[email protected]>
> >Cc: [email protected]; [email protected]
> >Subject: Re: [PATCH] staging:kpc2000:Fix dubious x | !y sparse warning
> >
> >On Thu, Aug 01, 2019 at 12:06:06AM +0530, Harsh Jain wrote:
> >> Bitwise OR(|) operation with 0 always yield same result.
> >> It fixes dubious x | !y sparse warning.
> >>
> >> Signed-off-by: Harsh Jain <[email protected]>
> >> ---
> >> drivers/staging/kpc2000/kpc2000_i2c.c | 16 +---------------
> >> 1 file changed, 1 insertion(+), 15 deletions(-)
> >>
> >> diff --git a/drivers/staging/kpc2000/kpc2000_i2c.c b/drivers/staging/kpc2000/kpc2000_i2c.c
> >> index b108da4..5f027d7c 100644
> >> --- a/drivers/staging/kpc2000/kpc2000_i2c.c
> >> +++ b/drivers/staging/kpc2000/kpc2000_i2c.c
> >> @@ -536,29 +536,15 @@ static u32 i801_func(struct i2c_adapter *adapter)
> >>
> >> u32 f =
> >> I2C_FUNC_I2C | /* 0x00000001 (I enabled this one) */
> >> - !I2C_FUNC_10BIT_ADDR | /* 0x00000002 */
> >> - !I2C_FUNC_PROTOCOL_MANGLING | /* 0x00000004 */
> >> ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) | /* 0x00000008 */
> >> - !I2C_FUNC_SMBUS_BLOCK_PROC_CALL | /* 0x00008000 */
> >> I2C_FUNC_SMBUS_QUICK | /* 0x00010000 */
> >> - !I2C_FUNC_SMBUS_READ_BYTE | /* 0x00020000 */
> >> - !I2C_FUNC_SMBUS_WRITE_BYTE | /* 0x00040000 */
> >> - !I2C_FUNC_SMBUS_READ_BYTE_DATA | /* 0x00080000 */
> >> - !I2C_FUNC_SMBUS_WRITE_BYTE_DATA | /* 0x00100000 */
> >> - !I2C_FUNC_SMBUS_READ_WORD_DATA | /* 0x00200000 */
> >> - !I2C_FUNC_SMBUS_WRITE_WORD_DATA | /* 0x00400000 */
> >> - !I2C_FUNC_SMBUS_PROC_CALL | /* 0x00800000 */
> >> - !I2C_FUNC_SMBUS_READ_BLOCK_DATA | /* 0x01000000 */
> >> - !I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | /* 0x02000000 */
> >
> >This is ok, it is showing you that these bits are explicitly being not
> >set. Which is good, now you can go through the list and see that all
> >are accounted for.
> >
> >So I think this should stay as-is, thanks.
>
> I was going to say the same thing, but I didn't know what the kernel style guideline was.
> Would Linus prefer this style or would commenting them out be preferred?
> Seems like the sparse warnings means the current style is not acceptable?
>
Sparse is just warning that you really are not doing anything here, in
case you think you are, as it's a common pattern for bugs.
So all should be fine, don't worry about it for now.
thanks,
greg k-h
On Thu, Aug 01, 2019 at 12:06:06AM +0530, Harsh Jain wrote:
> Bitwise OR(|) operation with 0 always yield same result.
> It fixes dubious x | !y sparse warning.
>
> Signed-off-by: Harsh Jain <[email protected]>
> ---
> drivers/staging/kpc2000/kpc2000_i2c.c | 16 +---------------
> 1 file changed, 1 insertion(+), 15 deletions(-)
>
> diff --git a/drivers/staging/kpc2000/kpc2000_i2c.c b/drivers/staging/kpc2000/kpc2000_i2c.c
> index b108da4..5f027d7c 100644
> --- a/drivers/staging/kpc2000/kpc2000_i2c.c
> +++ b/drivers/staging/kpc2000/kpc2000_i2c.c
> @@ -536,29 +536,15 @@ static u32 i801_func(struct i2c_adapter *adapter)
>
> u32 f =
> I2C_FUNC_I2C | /* 0x00000001 (I enabled this one) */
> - !I2C_FUNC_10BIT_ADDR | /* 0x00000002 */
> - !I2C_FUNC_PROTOCOL_MANGLING | /* 0x00000004 */
> ((priv->features & FEATURE_SMBUS_PEC) ? I2C_FUNC_SMBUS_PEC : 0) | /* 0x00000008 */
> - !I2C_FUNC_SMBUS_BLOCK_PROC_CALL | /* 0x00008000 */
> I2C_FUNC_SMBUS_QUICK | /* 0x00010000 */
> - !I2C_FUNC_SMBUS_READ_BYTE | /* 0x00020000 */
> - !I2C_FUNC_SMBUS_WRITE_BYTE | /* 0x00040000 */
> - !I2C_FUNC_SMBUS_READ_BYTE_DATA | /* 0x00080000 */
> - !I2C_FUNC_SMBUS_WRITE_BYTE_DATA | /* 0x00100000 */
> - !I2C_FUNC_SMBUS_READ_WORD_DATA | /* 0x00200000 */
> - !I2C_FUNC_SMBUS_WRITE_WORD_DATA | /* 0x00400000 */
> - !I2C_FUNC_SMBUS_PROC_CALL | /* 0x00800000 */
> - !I2C_FUNC_SMBUS_READ_BLOCK_DATA | /* 0x01000000 */
> - !I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | /* 0x02000000 */
This is ok, it is showing you that these bits are explicitly being not
set. Which is good, now you can go through the list and see that all
are accounted for.
So I think this should stay as-is, thanks.
greg k-h