Messages in this thread | | | Date | Sun, 7 Oct 2012 18:50:31 +0200 (CEST) | From | Julia Lawall <> | Subject | Re: [PATCH 9/13] drivers/media/tuners/fc0011.c: use macros for i2c_msg initialization |
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On Sun, 7 Oct 2012, walter harms wrote:
> > > Am 07.10.2012 17:38, schrieb Julia Lawall: >> From: Julia Lawall <Julia.Lawall@lip6.fr> >> >> 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 in each case. >> >> 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@lip6.fr> >> >> --- >> drivers/media/tuners/fc0011.c | 9 +++------ >> 1 file changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/media/tuners/fc0011.c b/drivers/media/tuners/fc0011.c >> index e488254..5dbba98 100644 >> --- a/drivers/media/tuners/fc0011.c >> +++ b/drivers/media/tuners/fc0011.c >> @@ -80,8 +80,7 @@ struct fc0011_priv { >> static int fc0011_writereg(struct fc0011_priv *priv, u8 reg, u8 val) >> { >> u8 buf[2] = { reg, val }; >> - struct i2c_msg msg = { .addr = priv->addr, >> - .flags = 0, .buf = buf, .len = 2 }; >> + struct i2c_msg msg = I2C_MSG_WRITE(priv->addr, buf, sizeof(buf)); >> >> if (i2c_transfer(priv->i2c, &msg, 1) != 1) { >> dev_err(&priv->i2c->dev, >> @@ -97,10 +96,8 @@ static int fc0011_readreg(struct fc0011_priv *priv, u8 reg, u8 *val) >> { >> u8 dummy; >> struct i2c_msg msg[2] = { >> - { .addr = priv->addr, >> - .flags = 0, .buf = ®, .len = 1 }, >> - { .addr = priv->addr, >> - .flags = I2C_M_RD, .buf = val ? : &dummy, .len = 1 }, >> + I2C_MSG_WRITE(priv->addr, ®, sizeof(reg)), >> + I2C_MSG_READ(priv->addr, val ? : &dummy, sizeof(dummy)), >> }; >> > > This dummy looks strange, can it be that this is used uninitialised ?
I'm not sure to understand the question. The read, when it happens in i2c_transfer will initialize dummy. On the other hand, I don't know what i2c_transfer does when the buffer is NULL and the size is 1. It does not look very elegant at least.
julia
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