On Sat, 8 Feb 2014 12:53:52 +0100, Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx> wrote:
> Today we only check if the linux,stdout-path property is present and retreive
> the node. But the DT specification allow to pass the serial options too as
> this
> linux,stdout-path = &UART0;
>
> or with options
>
> inux,stdout-path = "/plb@0/serial@84000000:115200";
typo. :-)
>
> So update the parsing to support and also the backward compatible stdout-path
> property.
Looks reasonable to me. Comment below, but otherwise:
Acked-by: Grant Likely <grant.likely@xxxxxxxxxx>
>
> Cc: linux-serial@xxxxxxxxxxxxxxx
> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@xxxxxxxxxxxx>
> ---
> drivers/of/base.c | 57 +++++++++++++++++++++++++++++++++++++++++++++---------
> include/linux/of.h | 4 ++--
> 2 files changed, 50 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index ff85450..ab9ff2f 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -34,6 +34,7 @@ EXPORT_SYMBOL(of_allnodes);
> struct device_node *of_chosen;
> struct device_node *of_aliases;
> static struct device_node *of_stdout;
> +static char *of_stdout_option;
>
> DEFINE_MUTEX(of_aliases_mutex);
>
> @@ -1783,6 +1784,45 @@ static void of_alias_add(struct alias_prop *ap, struct device_node *np,
> }
>
> /**
> + * of_stdout_path_scan - check if a device node matches the
> + * linux,stdout-path property and parse it
> + */
> +static void of_stdout_path_scan(void)
> +{
> + const char *name;
> + const char *tmp;
> + const char *tmp_option;
> +
> + name = of_get_property(of_chosen, "linux,stdout-path", NULL);
> + if (!name)
> + name = of_get_property(of_chosen, "stdout-path", NULL);
Should protect against unterminated strings. Use of_property_read_string()
> +
> + if (!name)
> + return;
> +
> + tmp_option = strchr(name, ':');
> +
> + if (!tmp_option) {
> + of_stdout = of_find_node_by_path(name);
> + return;
> + }
> +
> + tmp = kstrndup(name, strlen(name) - strlen(tmp_option), GFP_KERNEL);
> + if (!tmp)
> + return;
Having to do a strdup is kind of ugly and expensive when the only
problem is the terminating colon. I would rather see
of_find_node_by_path modified to do the right thing by ignoring the
colon which is illegal in path names anyway.
> +
> + of_stdout = of_find_node_by_path(tmp);
> + if (!of_stdout)
> + goto out;
> +
> + tmp_option++;
> + of_stdout_option = kstrdup(tmp_option, GFP_KERNEL);
The strdup is unnecessary. tmp_option is already null terminated, is
immutable, and contains the data you need.
> +
> +out:
> + kfree(tmp);
Please reverse the to eliminate the non-error goto:
of_stdout = of_find_node_by_path(tmp);
if (of_stdout)
of_stdout_option = tmp_option++;
kfree(tmp);
> +}
> +
> +/**
> * of_alias_scan - Scan all properties of 'aliases' node
> *
> * The function scans all the properties of 'aliases' node and populate
> @@ -1800,13 +1840,8 @@ void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
> if (of_chosen == NULL)
> of_chosen = of_find_node_by_path("/chosen@0");
>
> - if (of_chosen) {
> - const char *name;
> -
> - name = of_get_property(of_chosen, "linux,stdout-path", NULL);
> - if (name)
> - of_stdout = of_find_node_by_path(name);
> - }
> + if (of_chosen)
> + of_stdout_path_scan();
Move the of_chosen check directly into the function.
>
> of_aliases = of_find_node_by_path("/aliases");
> if (!of_aliases)
> @@ -1923,13 +1958,17 @@ EXPORT_SYMBOL_GPL(of_prop_next_string);
> * linux,stdout-path property
> *
> * Check if this device node matches the linux,stdout-path property
> - * in the chosen node. return true if yes, false otherwise.
> + * in the chosen node. return true if yes, false otherwise with the option if
> + * requested.
> */
> -int of_device_is_stdout_path(struct device_node *dn)
> +int of_device_is_stdout_path(struct device_node *dn, char** option)
> {
> if (!of_stdout)
> return false;
>
> + if (option)
> + *option = of_stdout_option;
> +
> return of_stdout == dn;
> }
> EXPORT_SYMBOL_GPL(of_device_is_stdout_path);
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 70c64ba..a8afe44 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -352,7 +352,7 @@ const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
> */
> const char *of_prop_next_string(struct property *prop, const char *cur);
>
> -int of_device_is_stdout_path(struct device_node *dn);
> +int of_device_is_stdout_path(struct device_node *dn, char** option);
>
> #else /* CONFIG_OF */
>
> @@ -542,7 +542,7 @@ static inline int of_machine_is_compatible(const char *compat)
> return 0;
> }
>
> -static inline int of_device_is_stdout_path(struct device_node *dn)
> +static inline int of_device_is_stdout_path(struct device_node *dn, char** option)
> {
> return 0;
> }
> --
> 1.9.rc1
>
>
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