Re: [PATCH v3 2/2] of: dynamic: Fix overlayed devices not probing because of fw_devlink

[Rob Herring <robh@kernel.org>]

On Thu, Apr 11, 2024 at 6:56 PM Saravana Kannan <saravanak@google.com> wrote:
>
> When an overlay is applied, if the target device has already probed
> successfully and bound to a device, then some of the fw_devlink logic
> that ran when the device was probed needs to be rerun. This allows newly
> created dangling consumers of the overlayed device tree nodes to be
> moved to become consumers of the target device.
>
> Fixes: 1a50d9403fb9 ("treewide: Fix probing of devices in DT overlays")
> Reported-by: Herve Codina <herve.codina@bootlin.com>
> Closes: https://lore.kernel.org/lkml/CAMuHMdXEnSD4rRJ-o90x4OprUacN_rJgyo8x6=9F9rZ+-KzjOg@mail.gmail.com/
> Closes: https://lore.kernel.org/all/20240221095137.616d2aaa@bootlin.com/
> Closes: https://lore.kernel.org/lkml/20240312151835.29ef62a0@bootlin.com/
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>  drivers/base/core.c    | 76 +++++++++++++++++++++++++++++++++++++-----
>  drivers/of/overlay.c   | 15 +++++++++
>  include/linux/fwnode.h |  1 +
>  3 files changed, 83 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 5f4e03336e68..1a646f393dd7 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -46,6 +46,8 @@ static bool fw_devlink_drv_reg_done;
>  static bool fw_devlink_best_effort;
>  static struct workqueue_struct *device_link_wq;
>
> +#define get_dev_from_fwnode(fwnode)    get_device((fwnode)->dev)

I think it is better to not have this wrapper. We want it to be clear
when we're acquiring a ref. I know get_device() does that, but I have
to look up what get_dev_from_fwnode() does exactly.

Side note: I didn't know fwnode has a ptr to the struct device. I
wonder if we can kill off of_find_device_by_node() using that. That's
for platform devices though.

Rob