Re: [PATCH v8 12/22] PCI, ACPI: debug print for installation of acpi root bridge's notifier

From: Rafael J. Wysocki
Date: Sat Jan 12 2013 - 18:31:57 EST


On Friday, January 11, 2013 02:40:39 PM Yinghai Lu wrote:
> From: Tang Chen <tangchen@xxxxxxxxxxxxxx>
>
> acpi_install_notify_handler() could fail. So check the exit status
> and give a better debug info.
>
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> ---
> drivers/acpi/pci_root.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index d30fb94..862abcc 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -943,6 +943,7 @@ static bool acpi_is_root_bridge_object(acpi_handle handle)
> static acpi_status __init
> find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
> {
> + acpi_status status;
> char objname[64];
> struct acpi_buffer buffer = { .length = sizeof(objname),
> .pointer = objname };
> @@ -955,9 +956,14 @@ find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
>
> acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
>
> - acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> - handle_hotplug_event_root, NULL);
> - printk(KERN_DEBUG "acpi root: %s notify handler installed\n", objname);
> + status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> + handle_hotplug_event_root, NULL);
> + if (ACPI_FAILURE(status))
> + printk(KERN_DEBUG "acpi root: %s notify handler is not installed, exit status: %u\n",
> + objname, (unsigned int)status);

If we print a message on failure, I don't think we need one on success.

Besides, please use pr_debug().

> + else
> + printk(KERN_DEBUG "acpi root: %s notify handler is installed\n",
> + objname);
>
> add_acpi_root_bridge(handle);

And I wonder what sens does this make to call add_acpi_root_bridge() here if we
haven't installed the notify handler for handle?

Rafael


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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