From: "Michael Büsch" <m@bues.ch>
To: Julia Lawall <julia.lawall@lip6.fr>
Cc: walter harms <wharms@bfs.de>,
kernel-janitors@vger.kernel.org, rmallon@gmail.com,
shubhrajyoti@ti.com,
Mauro Carvalho Chehab <mchehab@infradead.org>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 9/13] drivers/media/tuners/fc0011.c: use macros for i2c_msg initialization
Date: Sun, 7 Oct 2012 20:05:01 +0200 [thread overview]
Message-ID: <20121007200501.757a1ce6@milhouse> (raw)
In-Reply-To: <alpine.DEB.2.02.1210071845030.2745@localhost6.localdomain6>
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On Sun, 7 Oct 2012 18:50:31 +0200 (CEST)
Julia Lawall <julia.lawall@lip6.fr> wrote:
> >> @@ -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.
Well its use case is if you only care about the side effects and not the actual data
returned by the read operation.
--
Greetings, Michael.
PGP encryption is encouraged / 908D8B0E
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next prev parent reply other threads:[~2012-10-07 18:27 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-07 15:38 [PATCH 0/11] introduce macros for i2c_msg initialization Julia Lawall
2012-10-07 15:38 ` [PATCH 13/13] drivers/media/tuners/e4000.c: use " Julia Lawall
2012-10-07 16:33 ` walter harms
2012-10-07 16:44 ` Julia Lawall
2012-10-07 17:13 ` walter harms
2012-10-07 17:18 ` Julia Lawall
2012-10-07 18:16 ` Joe Perches
2012-10-07 18:56 ` Julia Lawall
2012-10-07 21:39 ` Joe Perches
2012-10-07 21:43 ` Julia Lawall
2012-10-07 21:51 ` Joe Perches
2012-10-08 1:56 ` Mauro Carvalho Chehab
2012-10-08 2:11 ` Ryan Mallon
2012-10-08 7:54 ` Antti Palosaari
2012-10-08 8:31 ` Julia Lawall
2012-10-09 23:32 ` Mauro Carvalho Chehab
2012-10-11 6:45 ` Julia Lawall
2012-12-18 11:46 ` Jean Delvare
2012-12-18 12:36 ` Julia Lawall
2012-12-18 13:13 ` Wolfram Sang
2012-10-09 23:50 ` Mauro Carvalho Chehab
2012-10-08 5:04 ` Julia Lawall
2012-10-07 21:49 ` Ryan Mallon
2012-10-07 21:52 ` Ryan Mallon
2012-10-07 15:38 ` [PATCH 2/13] drivers/media/tuners/mxl5007t.c: " Julia Lawall
2012-10-09 12:30 ` Jean Delvare
2012-10-09 12:50 ` Julia Lawall
2012-10-07 15:38 ` [PATCH 3/13] drivers/media/tuners/qt1010.c: " Julia Lawall
2012-10-07 21:55 ` Ryan Mallon
2012-10-08 5:05 ` Julia Lawall
2012-10-08 5:13 ` Ryan Mallon
2012-10-08 5:24 ` Julia Lawall
2012-10-09 12:12 ` Jean Delvare
2012-10-09 12:51 ` Julia Lawall
2012-10-07 15:38 ` [PATCH 4/13] drivers/media/tuners/tda18212.c: " Julia Lawall
2012-10-07 15:38 ` [PATCH 5/13] drivers/media/tuners: " Julia Lawall
2012-10-07 22:05 ` Ryan Mallon
2012-10-08 5:12 ` Julia Lawall
2012-10-07 15:38 ` [PATCH 6/13] drivers/media/tuners/tda18271-common.c: " Julia Lawall
2012-10-07 15:38 ` [PATCH 7/13] drivers/media/tuners/tua9001.c: " Julia Lawall
2012-10-07 15:38 ` [PATCH 8/13] drivers/media/tuners/fc2580.c: " Julia Lawall
2012-10-07 15:38 ` [PATCH 9/13] drivers/media/tuners/fc0011.c: " Julia Lawall
2012-10-07 16:43 ` walter harms
2012-10-07 16:50 ` Julia Lawall
2012-10-07 16:54 ` walter harms
2012-10-07 18:05 ` Michael Büsch [this message]
2012-10-09 12:06 ` Jean Delvare
2012-10-07 15:38 ` [PATCH 10/13] drivers/media/tuners/tda8290.c: " Julia Lawall
2012-10-07 15:38 ` [PATCH 11/13] drivers/media/tuners/tda18218.c: " Julia Lawall
2012-10-07 15:38 ` [PATCH 12/13] drivers/media/tuners/max2165.c: " Julia Lawall
2012-10-07 22:14 ` Ryan Mallon
2012-10-08 5:13 ` Julia Lawall
2012-10-09 15:32 ` [PATCH 0/11] introduce " Jean Delvare
2012-10-09 15:43 ` Julia Lawall
2012-10-22 9:18 ` Julia Lawall
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