Re: [PATCH v3 2/2] acpi: nfit: Add support for hot-add

[Dan Williams <dan.j.williams@intel.com>]

Rafael, awaiting your ack...

Vishal, one thing I'll fix up on applying...

On Tue, Oct 27, 2015 at 3:58 PM, Vishal Verma <vishal.l.verma@intel.com> wrote:
> Add a .notify callback to the acpi_nfit_driver that gets called on a
> hotplug event. From this, evaluate the _FIT ACPI method which returns
> the updated NFIT with handles for the hot-plugged NVDIMM.
>
> Iterate over the new NFIT, and add any new tables found, and
> register/enable the corresponding regions.
>
> In the nfit test framework, after normal initialization, update the NFIT
> with a new hot-plugged NVDIMM, and directly call into the driver to
> update its view of the available regions.
>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Cc: Toshi Kani <toshi.kani@hpe.com>
> Cc: Elliott, Robert <elliott@hpe.com>
> Cc: Jeff Moyer <jmoyer@redhat.com>
> Cc: <linux-acpi@vger.kernel.org>
> Cc: <linux-nvdimm@lists.01.org>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
[..]

> +static int acpi_nfit_add(struct acpi_device *adev)
> +{
> +       struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
> +       struct acpi_nfit_desc *acpi_desc;
> +       struct device *dev = &adev->dev;
> +       struct acpi_table_header *tbl;
> +       acpi_status status = AE_OK;
> +       acpi_size sz;
> +       int rc = 0;
> +
> +       device_lock(dev);

The device is already locked by the time we reach this point.  The
unit tests don't trip this path which might be why this wasn't seen
earlier.