Subject: [PATCH 1/3] of/base: Take NULL string into account for property with multiple strings

From: [email-masked] (Tony Lindgren)
Date: Wed, 14 Dec 2011 10:18:22 -0800

* Benoit Cousson <[email-masked]> [111205 05:53]:
> The current implementation just ignore any NULL string inserted in a
> multiple strings property.
> In some cases we can have a property with a fix number of strings but
> not necessarily used, like for example in a list of valid pinmux modes.
> 
>  prop = "uart_rx", "uart_tx", "", "", "safe_mode";
> 
> Do no skip NULL string and take them into account in
> of_property_read_string_index and of_property_count_strings.
> 
> Reported-by: Tony Lindgren <[email-masked]>
> Signed-off-by: Benoit Cousson <[email-masked]>
> Cc: Grant Likely <[email-masked]>
> Cc: Rob Herring <[email-masked]>

This fix should be merged before people start doing workarounds
in drivers for this:

Tested-by: Tony Lindgren <[email-masked]>

> ---
>  drivers/of/base.c |    8 +++-----
>  1 files changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 9b6588e..b707243 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -752,7 +752,7 @@ int of_property_read_string_index(struct device_node *np, const char *propname,
>  
>  	for (i = 0; total < prop->length; total += l, p += l) {
>  		l = strlen(p) + 1;
> -		if ((*p != 0) && (i++ == index)) {
> +		if (i++ == index) {
>  			*output = p;
>  			return 0;
>  		}
> @@ -790,11 +790,9 @@ int of_property_count_strings(struct device_node *np, const char *propname)
>  
>  	p = prop->value;
>  
> -	for (i = 0; total < prop->length; total += l, p += l) {
> +	for (i = 0; total < prop->length; total += l, p += l, i++)
>  		l = strlen(p) + 1;
> -		if (*p != 0)
> -			i++;
> -	}
> +
>  	return i;
>  }
>  EXPORT_SYMBOL_GPL(of_property_count_strings);
> -- 
> 1.7.0.4
>