i2c: core: fix a code to suppress a warning

PATCH Superseded Andy Shevchenko 4 participants 7 messages Sep 15, 2015 4 messages not in the archive

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Andy Shevchenko

author

2015-09-15 10:11 UTC #0 lore raw

PATCH 1/1 i2c: core: fix a code to suppress a warning

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-VuQAYsv1563Yd54FQh9/[email protected]>

---
 drivers/i2c/i2c-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/i2c/i2c-core.c +1 -1

index 3a4c54e..d13a8a0 100644
@@ -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 */

Signature · 1 line

2.5.1

A message that is not in the archive (sent off-list or not yet received): 1442311867-60185-1-git-send-email-andriy.shevchenko-VuQAYsv1563Yd54FQh9/[email protected]

Alexander Sverdlin

Reviewed-by

2015-09-15 11:23 UTC #2 lore raw

Quoted 6 lines · EXT Andy Shevchenko

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-VuQAYsv1563Yd54FQh9/[email protected]>

Reviewed-by Alexander Sverdlin <[email protected]>

Quoted 17 lines

---
 drivers/i2c/i2c-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/i2c/i2c-core.c +1 -1

index 3a4c54e..d13a8a0 100644
@@ -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 */

Signature · 2 lines

Best regards,
Alexander Sverdlin.

Vladimir Zapolskiy

2015-09-15 11:25 UTC #3 lore raw

In reply to a message not in the archive

Hello Andy,

Quoted 16 lines · Andy Shevchenko

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-VuQAYsv1563Yd54FQh9/[email protected]>
---
 drivers/i2c/i2c-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/i2c/i2c-core.c +0 -0
index 3a4c54e..d13a8a0 100644

drivers/i2c/i2c-core.c static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) · line 2597

Quoted 8 lines

drivers/i2c/i2c-core.c +1 -1

@@ -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

A message that is not in the archive (sent off-list or not yet received): [email protected]

Andy Shevchenko

author

2015-09-15 12:06 UTC #5 lore raw

Quoted 27 lines · Vladimir Zapolskiy

Hello Andy,
Quoted 24 lines · Andy Shevchenko
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-VuQAYsv1563Yd54FQh9/[email protected]>
---
 drivers/i2c/i2c-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/i2c/i2c-core.c +1 -1
index 3a4c54e..d13a8a0 100644
@@ -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);

Quoted 5 lines

Quoted 2 lines
/* 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.

Quoted 4 lines

--
With best wishes,
Vladimir

Signature · 2 lines

Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/[email protected]>
Intel Finland Oy

A message that is not in the archive (sent off-list or not yet received): 1442318818.8361.29.camel-VuQAYsv1563Yd54FQh9/[email protected]

Vladimir Zapolskiy

2015-09-15 12:47 UTC #7 lore raw

Quoted 28 lines · Andy Shevchenko

Quoted 27 lines · Vladimir Zapolskiy
Hello Andy,
Quoted 24 lines · Andy Shevchenko
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-VuQAYsv1563Yd54FQh9/[email protected]>
---
 drivers/i2c/i2c-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/i2c/i2c-core.c +1 -1
index 3a4c54e..d13a8a0 100644
@@ -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);

Quoted 8 lines

Quoted 5 lines
Quoted 2 lines
/* 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

A message that is not in the archive (sent off-list or not yet received): [email protected]

Wolfram Sang

2015-09-15 13:00 UTC #9 lore raw

Quoted 10 lines

Quoted 6 lines
Quoted 3 lines
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...

Andy Shevchenko

author

2015-09-15 13:34 UTC #10 lore raw

Quoted 14 lines · Wolfram Sang

Quoted 5 lines
Quoted 5 lines
Quoted 4 lines
I2C_M_RD is defined as 1, probably (msg->flags & I2C_M_RD) is good
enough here.
Quoted 8 lines
Quoted 3 lines
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.

Quoted 4 lines

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.

Quoted 2 lines

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.

Signature · 2 lines

Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/[email protected]>
Intel Finland Oy