Re: [PATCH 3/13] drivers/media/tuners/qt1010.c: use macros for i2c_msg initialization

On 08/10/12 16:05, Julia Lawall wrote:

On Mon, 8 Oct 2012, Ryan Mallon wrote:

quoted

On 08/10/12 02:38, Julia Lawall wrote:

quoted

From: Julia Lawall <redacted>

Introduce use of I2c_MSG_READ/WRITE/OP, for readability.

A length expressed as an explicit constant is also re-expressed as
the size
of the buffer, when this is possible.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression a,b,c;
identifier x;
@@

struct i2c_msg x =
- {.addr = a, .buf = b, .len = c, .flags = I2C_M_RD}
+ I2C_MSG_READ(a,b,c)
 ;

@@
expression a,b,c;
identifier x;
@@

struct i2c_msg x =
- {.addr = a, .buf = b, .len = c, .flags = 0}
+ I2C_MSG_WRITE(a,b,c)
 ;

@@
expression a,b,c,d;
identifier x;
@@

struct i2c_msg x =
- {.addr = a, .buf = b, .len = c, .flags = d}
+ I2C_MSG_OP(a,b,c,d)
 ;
// </smpl>

Signed-off-by: Julia Lawall <redacted>

---
 drivers/media/tuners/qt1010.c |   10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/media/tuners/qt1010.c

b/drivers/media/tuners/qt1010.c
index bc419f8..37ff254 100644

--- a/drivers/media/tuners/qt1010.c
+++ b/drivers/media/tuners/qt1010.c

@@ -25,10 +25,8 @@
 static int qt1010_readreg(struct qt1010_priv *priv, u8 reg, u8 *val)
 {
     struct i2c_msg msg[2] = {
-        { .addr = priv->cfg->i2c_address,
-          .flags = 0, .buf = &reg, .len = 1 },
-        { .addr = priv->cfg->i2c_address,
-          .flags = I2C_M_RD, .buf = val, .len = 1 },
+        I2C_MSG_WRITE(priv->cfg->i2c_address, &reg, sizeof(reg)),
+        I2C_MSG_READ(priv->cfg->i2c_address, val, 1),

This is a bit inconsistent. For single length values we should either
consistently use sizeof(val) or 1. This has both.

val is a pointer.  It does not have size 1.

Sorry, I mean either:

	I2C_MSG_WRITE(priv->cfg->i2c_address, &reg, sizeof(reg)),
	I2C_MSG_READ(priv->cfg->i2c_address, val, sizeof(*val)),

or:

	I2C_MSG_WRITE(priv->cfg->i2c_address, &reg, 1),
	I2C_MSG_READ(priv->cfg->i2c_address, val, 1),

~Ryan