Messages in this thread | | | Date | Sun, 7 Oct 2012 20:05:01 +0200 | From | Michael Büsch <> | 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 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.
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