Re: [PATCH v5 02/12] libata: bind the Linux device tree to the ACPI device tree

Dan Williams
2012-06-20T23:50:50Z

On Sun, Jun 17, 2012 at 11:25 PM, Lin Ming <ming.m.lin@intel.com> wrote:
> From: Matthew Garrett <mjg@redhat.com>
>
> Associate the ACPI device tree and libata devices.
> This patch uses the generic ACPI glue framework to do so.
>
> Signed-off-by: Matthew Garrett <mjg@redhat.com>
> Signed-off-by: Holger Macht <holger@homac.de>
> Signed-off-by: Lin Ming <ming.m.lin@intel.com>
> ---
>
> Changelog:
>
> - fixed crash reported at https://lkml.org/lkml/2012/2/24/2 (Aaron Lu)
> - rename is_pci_ata to compat_pci_ata (Alan Cox)
>
>  drivers/acpi/glue.c       |    4 +-
>  drivers/ata/libata-acpi.c |  125 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/ata/libata-core.c |    3 ++
>  drivers/ata/libata.h      |    4 ++
>  4 files changed, 134 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
> index 1564e09..18d6812 100644
> --- a/drivers/acpi/glue.c
> +++ b/drivers/acpi/glue.c
[..]
> +static int ata_acpi_bind_host(struct device *dev, int host, acpi_handle *handle)
> +{
> +       struct Scsi_Host *shost = dev_to_shost(dev);
> +       struct ata_port *ap = ata_shost_to_port(shost);
> +
> +       if (ap->flags & ATA_FLAG_ACPI_SATA)
> +               return -ENODEV;
> +
> +       *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), ap->port_no);
> +
> +       if (!*handle)
> +               return -ENODEV;
> +
> +       return 0;
> +}

I think this patch should be squashed with patch 4, right? That is if
we keep the hard-coded ->parent chasing...

> +static int ata_acpi_find_device(struct device *dev, acpi_handle *handle)
> +{
> +       unsigned int host, channel, id, lun;
> +
> +       if (sscanf(dev_name(dev), "host%u", &host) == 1) {
> +               if (!compat_pci_ata(dev->parent))
> +                       return -ENODEV;
> +
> +               return ata_acpi_bind_host(dev, host, handle);
> +       } else if (sscanf(dev_name(dev), "%d:%d:%d:%d",
> +                       &host, &channel, &id, &lun) == 4) {
> +               if (!compat_pci_ata(dev->parent->parent->parent))
> +                       return -ENODEV;

...this looks like it should be using a dev_to_ata_port() helper which
like dev_to_shost() skips the need to remember just how many parents
until we get back to our ata_port, scsi_host, etc.

--
Dan