i2c: uniphier[-f]: fix bool logic calculation

Message ID 1476851911-21729-1-git-send-email-yamada.masahiro@socionext.com
State New
Headers show

Commit Message

Masahiro Yamada Oct. 19, 2016, 4:38 a.m.
This code is working, but it should not depend on how "bool" is
typedef'ed, or the bit position of I2C_M_RD.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

---

 drivers/i2c/busses/i2c-uniphier-f.c | 2 +-
 drivers/i2c/busses/i2c-uniphier.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

-- 
1.9.1

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Comments

Joe Perches Dec. 20, 2016, 5:55 p.m. | #1
On Wed, 2016-12-21 at 01:20 +0900, Masahiro Yamada wrote:
> Hi.

> 

> I have not got any comment, but does this seem

> a right thing to do?


> This code is working, but it should not depend on how "bool" is

> typedef'ed, or the bit position of I2C_M_RD.


<shrug>

I think bool can be guaranteed to be _Bool.

So a change not necessary as the original code
has a c90 guarantee of the same result.

6.3.1.2 Boolean type
1
When any scalar value is converted to _Bool, the result is 0 if the value compares equal
to 0; otherwise, the result is 1.


> 2016-10-19 13:38 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:

[]
> > diff --git a/drivers/i2c/busses/i2c-uniphier-f.c b/drivers/i2c/busses/i2c-uniphier-f.c

[]
> > @@ -309,7 +309,7 @@ static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap,

> >                                          struct i2c_msg *msg, bool stop)

> >  {

> >         struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);

> > -       bool is_read = msg->flags & I2C_M_RD;

> > +       bool is_read = !!(msg->flags & I2C_M_RD);

> >         unsigned long time_left;

> > 

> >         dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n",


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Masahiro Yamada Dec. 21, 2016, 3:39 p.m. | #2
Hi Joe,


2016-12-21 2:55 GMT+09:00 Joe Perches <joe@perches.com>:
> On Wed, 2016-12-21 at 01:20 +0900, Masahiro Yamada wrote:

>> Hi.

>>

>> I have not got any comment, but does this seem

>> a right thing to do?

>

>> This code is working, but it should not depend on how "bool" is

>> typedef'ed, or the bit position of I2C_M_RD.

>

> <shrug>

>

> I think bool can be guaranteed to be _Bool.

>

> So a change not necessary as the original code

> has a c90 guarantee of the same result.

>

> 6.3.1.2 Boolean type

> 1

> When any scalar value is converted to _Bool, the result is 0 if the value compares equal

> to 0; otherwise, the result is 1.

>


Thanks for your comments!

_Bool works very nicely.

I have seen some (not very nice) projects
that define like "typedef char bool;"

So, I was wondering if I should write code
that works regardless how bool is defined.
Just my two cents.

-- 
Best Regards
Masahiro Yamada
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Patch hide | download patch | download mbox

diff --git a/drivers/i2c/busses/i2c-uniphier-f.c b/drivers/i2c/busses/i2c-uniphier-f.c
index db9105e..b54448e 100644
--- a/drivers/i2c/busses/i2c-uniphier-f.c
+++ b/drivers/i2c/busses/i2c-uniphier-f.c
@@ -309,7 +309,7 @@  static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap,
 					 struct i2c_msg *msg, bool stop)
 {
 	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
-	bool is_read = msg->flags & I2C_M_RD;
+	bool is_read = !!(msg->flags & I2C_M_RD);
 	unsigned long time_left;
 
 	dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n",
diff --git a/drivers/i2c/busses/i2c-uniphier.c b/drivers/i2c/busses/i2c-uniphier.c
index 56e92af..cc80bb2 100644
--- a/drivers/i2c/busses/i2c-uniphier.c
+++ b/drivers/i2c/busses/i2c-uniphier.c
@@ -177,7 +177,7 @@  static int uniphier_i2c_stop(struct i2c_adapter *adap)
 static int uniphier_i2c_master_xfer_one(struct i2c_adapter *adap,
 					struct i2c_msg *msg, bool stop)
 {
-	bool is_read = msg->flags & I2C_M_RD;
+	bool is_read = !!(msg->flags & I2C_M_RD);
 	bool recovery = false;
 	int ret;