On Sat, Nov 08, 2014 at 07:33:22PM +0100, Jean-Francois Moine wrote: > Some device nodes are sometimes referenced by const pointers. > > This patch avoids to cast these pointers when calling the functions > of_clk_get() and of_node_put(). NAK. Firstly, of_node_put contains a kref, which is /definitely/ not a const item when kobject_put() is called on it. Inside the kobject is a kref, which kobject_put() will call kref_put() on. kref_put() in turn will internally call atomic_sub_and_test() on a value embedded within the kref struct. Ergo, of_node_put() modifies the struct device_node contents. Therefore, of_node_put() definitely not treating the data pointed to as read-only, and therefore it is completely inappropriate for it to be marked "const". What this then means is that it fundamentally undermines the idea of storing the pointer to a device_node as a const pointer, as the device node must always be modified when you're done with it (because it's a ref-counted structure.) So, having it const in your code is a bug. What this also means is that every other place that you've added const below is also very dubious. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
