Re: [PATCH] mtd: nxp-spifi: decrement flash_np refcnt on error paths

From: Alexey Khoroshilov
Date: Wed May 09 2018 - 10:35:50 EST


On 09.05.2018 12:42, Boris Brezillon wrote:
> On Tue, 8 May 2018 23:47:36 +0300
> Alexey Khoroshilov <khoroshilov@xxxxxxxxx> wrote:
>
>> nxp_spifi_probe() increments refcnt of SPI flash device node by
>> of_get_next_available_child() and then it passes the node
>> to mtd device in nxp_spifi_setup_flash().
>> But if a failure happens before mtd_device_register() succeed,
>> the refcnt is left undecremented.
>
> Why not doing that in the error path of the probe function? Also, you
> probably want to call of_node_put() in the ->remove() function.
>


You are right.

I believed that after successful mtd_device_register()
the node is managed by mtd device. I missed that it calls of_node_get()
in add_mtd_device() by itself.

I will prepare v2.
But I guess there is no need to have of_node_put() in ->remove(), since
probe() finishes its own usage of flash_np, while mtd_device incremented
refcnt by itself and will decrement it in ->remove() in
mtd_device_unregister(&spifi->nor.mtd). So, I would propose
of_node_put() on both successful and error path.

Thank you,
Alexey