Re: [PATCH 1/3] of: base: add support to get machine compatible string

From: Sekhar Nori
Date: Tue Nov 22 2016 - 10:07:18 EST

Hi Sudeep,

On Tuesday 22 November 2016 04:23 PM, Sudeep Holla wrote:
> On 22/11/16 10:41, Bartosz Golaszewski wrote:
>> Add a function allowing to retrieve the compatible string of the root
>> node of the device tree.
> Rob has queued [1] and it's in -next today. You can reuse that if you
> are planning to target this for v4.11 or just use open coding in your
> driver for v4.10 and target this move for v4.11 to avoid cross tree
> dependencies as I already mentioned in your previous thread.

I dont have your original patch in my mailbox, but I wonder if
returning a pointer to property string for a node whose reference has
already been released is safe to do? Probably not an issue for the root
node, but still feels counter-intuitive.

This is the code for reference:

+int of_machine_get_model_name(const char **model)
+ int error;
+ if (!of_node_get(of_root))
+ return -EINVAL;
+ error = of_property_read_string(of_root, "model", model);
+ if (error)
+ error = of_property_read_string_index(of_root, "compatible",
+ 0, model);
+ of_node_put(of_root);
+ return error;