[PATCH linux dev-4.7 v2] drivers/fsi: Remove hub devices during master unregister

[Joel Stanley]

On Wed, Mar 8, 2017 at 3:16 AM, Christopher Bostic
<cbostic at linux.vnet.ibm.com> wrote:
> All hub devices must be removed when the primary FSI master
> is being unregistered.  This ensures that the system is in
> a clean state when another scan is attempted.  Failure to do so
> will result in duplicate /sys device name errors.
>
> Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
> ---
> v2: Fix missing return in non void function warning
> ---
>  drivers/fsi/fsi-core.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
>
> diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
> index bd57b41..bbdf6b8 100644
> --- a/drivers/fsi/fsi-core.c
> +++ b/drivers/fsi/fsi-core.c
> @@ -84,6 +84,7 @@ struct fsi_master_hub {
>  #define to_fsi_master_hub(d) container_of(d, struct fsi_master_hub, master)
>  #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
>
> +static void fsi_master_unscan(struct fsi_master *master);
>  static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
>                 void *val, size_t size);
>  static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
> @@ -441,6 +442,7 @@ static int fsi_slave_scan(struct fsi_slave *slave)
>                         hub->dev.release = hub_master_release;
>                         hub->master.dev = &hub->dev;
>                         hub->master.dev->parent = &slave->dev;
> +                       dev_set_drvdata(&hub->dev, hub);
>                         rc = device_add(&hub->dev);
>                         if (rc)
>                                 return rc;
> @@ -739,6 +741,20 @@ static int fsi_master_scan(struct fsi_master *master)
>         return 0;
>  }
>
> +static int fsi_unregister_hubs(struct device *dev, void *data)
> +{
> +       struct fsi_master_hub *hub =
> +                               (struct fsi_master_hub *)dev_get_drvdata(dev);

dev_get_drvdata returns a void *, so there is no need to cast.

I fixed this up when applying.

> +       if (!hub)
> +               return 0;

Is this expected? Should it return an error?

> +
> +       device_del(dev);
> +       fsi_master_unscan(&hub->master);
> +
> +       return 0;
> +}
> +
>  static void fsi_master_unscan(struct fsi_master *master)
>  {
>         struct fsi_slave *slave, *slave_tmp;
> @@ -756,6 +772,8 @@ static void fsi_master_unscan(struct fsi_master *master)
>                         device_del(&fsi_dev->dev);
>                         put_device(&fsi_dev->dev);
>                 }
> +               /* Remove any hub masters */
> +               device_for_each_child(&slave->dev, NULL, fsi_unregister_hubs);
>                 device_unregister(&slave->dev);
>         }
>         master->slave_list = false;
> --
> 1.8.2.2
>