From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julia Lawall Date: Sun, 07 Oct 2012 16:50:31 +0000 Subject: Re: [PATCH 9/13] drivers/media/tuners/fc0011.c: use macros for i2c_msg initialization Message-Id: List-Id: References: <1349624323-15584-1-git-send-email-Julia.Lawall@lip6.fr> <1349624323-15584-11-git-send-email-Julia.Lawall@lip6.fr> <5071B147.3010708@bfs.de> In-Reply-To: <5071B147.3010708@bfs.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: walter harms Cc: Julia Lawall , Michael Buesch , kernel-janitors@vger.kernel.org, rmallon@gmail.com, shubhrajyoti@ti.com, Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org On Sun, 7 Oct 2012, walter harms wrote: > > > Am 07.10.2012 17:38, schrieb Julia Lawall: >> From: Julia Lawall >> >> 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/) >> >> // >> @@ >> 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) >> ; >> // >> >> Signed-off-by: Julia Lawall >> >> --- >> 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