Re: [PATCH 3/13] drivers/media/tuners/qt1010.c: use macros fori2c_msg initialization

From: Julia Lawall
Date: Mon Oct 08 2012 - 01:05:37 EST


On Mon, 8 Oct 2012, Ryan Mallon wrote:

On 08/10/12 02:38, Julia Lawall wrote:
From: Julia Lawall <Julia.Lawall@xxxxxxx>

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 <Julia.Lawall@xxxxxxx>

---
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.

julia
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