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From: Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>
To: Jon Smirl <jonsmirl-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Linux I2C <i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org>
Subject: Re: int vs uint
Date: Sun, 20 Jul 2008 17:23:56 +0100	[thread overview]
Message-ID: <20080720162356.GA8318@fluff.org.uk> (raw)
In-Reply-To: <9e4733910807191746oe5aca3av581bdc5cfab293c3-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On Sat, Jul 19, 2008 at 08:46:41PM -0400, Jon Smirl wrote:
> There are a lot places in the i2c API where int is used when the
> parameter can't be negative. For example, there are more....
> 
> /*
>  * The master routines are the ones normally used to transmit data to devices
>  * on a bus (or read from them). Apart from two basic transfer functions to
>  * transmit one message at a time, a more complex version can be used to
>  * transmit an arbitrary number of messages without interruption.
>  */
> extern int i2c_master_send(struct i2c_client *,const char* ,int);
> extern int i2c_master_recv(struct i2c_client *,char* ,int);
> 
> /* Transfer num messages.
>  */
> extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg
> *msgs, int num);
> 
> 	u8 level; 			/* nesting level for lockdep */
> 
> 
> Wouldn't these generate more efficient code if switched to uints?

I'm not sure, most of the time there's not a lot of difference
between the signed and unsigned case. If you can provide an example
of where this is actually true then I would be interested to see...

Technically, an unsigned int or simply an unsigned would be a
reasonable change given that you can't really have a minus number
of transfers.

-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

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  parent reply	other threads:[~2008-07-20 16:23 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-20  0:46 int vs uint Jon Smirl
     [not found] ` <9e4733910807191746oe5aca3av581bdc5cfab293c3-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-07-20 16:23   ` Ben Dooks [this message]
     [not found]     ` <20080720162356.GA8318-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
2008-07-20 16:44       ` Jon Smirl
     [not found]         ` <9e4733910807200944m71728a9eldd5a9099ff2829a5-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-07-20 16:47           ` Jon Smirl
     [not found]             ` <9e4733910807200947t7abeb0f3i8217766b5392096a-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2008-07-21  9:48               ` Ben Dooks
     [not found]                 ` <20080721094838.GB8318-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
2008-07-21 14:26                   ` Jon Smirl

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