[PATCH 1/3] i2cdetect: don't die on addresses already in use by drivers

[walter harms]

Am 25.05.2015 12:40, schrieb Bartosz Golaszewski:
> We can't use i2c_set_slave_addr() in i2cdetect, as we have to check for
> EBUSY after calling ioctl(I2C_SLAVE) and print 'UU' on busy addresses
> instead of bailing-out.
> 
> While we're at it: reorder definitions of local vars in i2cdetect_main().
> 
> function                                             old     new   delta
> i2cdetect_main                                       703     744     +41
> ------------------------------------------------------------------------------
> (add/remove: 0/0 grow/shrink: 1/0 up/down: 41/0)               Total: 41 bytes
>    text	   data	    bss	    dec	    hex	filename
>  826097	   4164	   9584	 839845	  cd0a5	busybox_old
>  826145	   4164	   9584	 839893	  cd0d5	busybox_unstripped
> 
> Signed-off-by: Bartosz Golaszewski <bartekgola at gmail.com>
> ---
>  miscutils/i2c_tools.c | 31 +++++++++++++++++++------------
>  1 file changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git a/miscutils/i2c_tools.c b/miscutils/i2c_tools.c
> index 7034dc9..b05968b 100644
> --- a/miscutils/i2c_tools.c
> +++ b/miscutils/i2c_tools.c
> @@ -355,6 +355,13 @@ static void i2c_set_pec(int fd, int pec)
>  				itoptr(pec ? 1 : 0),
>  				"can't set PEC");
>  }
> +
> +static void i2c_set_slave_addr(int fd, int addr, int force)
> +{
> +	ioctl_or_perror_and_die(fd, force ? I2C_SLAVE_FORCE : I2C_SLAVE,
> +				itoptr(addr),
> +				"can't set address to 0x%02x", addr);
> +}
>  #endif /* ENABLE_I2CGET || ENABLE_I2CSET || ENABLE_I2CDUMP */
>  
>  #if ENABLE_I2CGET || ENABLE_I2CSET
> @@ -390,13 +397,6 @@ static int i2c_dev_open(int i2cbus)
>  	return fd;
>  }
>  
> -static void i2c_set_slave_addr(int fd, int addr, int force)
> -{
> -	ioctl_or_perror_and_die(fd, force ? I2C_SLAVE_FORCE : I2C_SLAVE,
> -				itoptr(addr),
> -				"can't set address to 0x%02x", addr);
> -}
> -
>  /* Size reducing helpers for xxx_check_funcs(). */
>  static void get_funcs_matrix(int fd, unsigned long *funcs)
>  {
> @@ -1281,11 +1281,9 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
>  			      opt_F = (1 << 4), opt_l = (1 << 5);
>  	const char *const optstr = "yaqrFl";
>  
> -	int fd, bus_num, i, j, mode = DETECT_MODE_AUTO;
> -	int status;
> -	unsigned first = 0x00, last = 0x77;
> +	int fd, bus_num, i, j, mode = DETECT_MODE_AUTO, status;
> +	unsigned first = 0x00, last = 0x77, opts;
>  	unsigned long funcs;
> -	unsigned opts;
>  
>  	opt_complementary = "q--r:r--q:" /* mutually exclusive */
>  			"?3"; /* up to 3 args */
> @@ -1370,7 +1368,16 @@ int i2cdetect_main(int argc UNUSED_PARAM, char **argv)
>  				continue;
>  			}
>  
> -			i2c_set_slave_addr(fd, i + j, 0);
> +			status = ioctl(fd, I2C_SLAVE, itoptr(i + j));
> +			if (status < 0) {
> +				if (errno == EBUSY) {
> +					printf("UU ");
> +					continue;
> +				} else {
> +					bb_perror_msg_and_die(
> +						"can't set address to 0x%02x", i + j);
> +				}
> +			}


I guess you can drop the else and simply
call bb_perror_msg_and_die(). that reduces the indent
a bit.

re,
 wh


>  			switch (mode) {
>  			case DETECT_MODE_READ: