Re: [PATCH 1/4] ACPI: EC: Add ec_get_handle()

[Corentin Chary]

On Fri, Dec 16, 2011 at 2:19 PM, Thomas Renninger <trenn@xxxxxxx> wrote:
> On Friday, December 16, 2011 01:33:33 AM Matthew Garrett wrote:
>> On Fri, Dec 16, 2011 at 01:22:35AM +0100, Thomas Renninger wrote:
>>
>> > I think best is to move the thinkpad implementation of getting
>> > ACPI handles based on HIDs to osl.c and make it global.
>> > I'll send patches.
>> > Please review them carefully, they are only compile tested.
>>
>> The ec driver is already finding the hardware on the basis of the HID -
>> is there any reason to do this twice rather than just exporting the
>> information the ec driver already has?
>
> I don't object to export ec_handle, but thinkpad_acpi.c should get
> adjusted as well.
>
> I had a closer look and can come up with a replacement for acpi_get_devices
> using bus.c matching function bus_find_device() avoiding the namespace
> walk.
>
> What do you think about this one?
> I found these occurences of acpi_get_devices, which I would
> adjust in follow up patches if it's worth it:
> drivers/char/agp/hp-agp.c: Â Â Âacpi_get_devices("HWP0003", zx1_gart_probe, "HWP0003", NULL);
> drivers/char/agp/hp-agp.c: Â Â Âacpi_get_devices("HWP0007", zx1_gart_probe, "HWP0007", NULL);
> drivers/acpi/processor_core.c: Âacpi_get_devices("ACPI0007", early_init_pdc, NULL, NULL);
> drivers/platform/x86/eeepc-wmi.c: Â Â Â status = acpi_get_devices(EEEPC_ACPI_HID, eeepc_wmi_parse_device,

I like the idea, that would remove some code from eeepc-wmi (and others) :).

> drivers/platform/x86/thinkpad_acpi.c: Â status = acpi_get_devices(hid, tpacpi_acpi_handle_locate_callback,
>
>
> Argh, these are called before ACPI objects are initialized
> (or parsed at all) and won't work:
> drivers/acpi/ec.c: Â Â Âstatus = acpi_get_devices(ec_device_ids[0].id, ec_parse_device,
> arch/ia64/kernel/acpi.c: Â Â Â Âacpi_get_devices(NULL, acpi_map_iosapic, NULL, NULL);
> drivers/pnp/pnpacpi/core.c: Â Â acpi_get_devices(NULL, pnpacpi_add_device_handler, NULL, NULL);
> arch/x86/pci/mmconfig-shared.c: acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
> arch/x86/pci/mmconfig-shared.c: Â Â Â Â acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
> arch/ia64/sn/kernel/io_acpi_init.c: Â Â acpi_get_devices("SGIHUB", sn_acpi_hubdev_init, NULL, NULL);
> arch/ia64/sn/kernel/io_acpi_init.c: Â Â acpi_get_devices("SGITIO", sn_acpi_hubdev_init, NULL, NULL);
>
> Looks like it's not worth it.
> I paste my patch anyway, if there is any use-case,
> it's already tested and works...:
>
> ---
> ACPI: Provide an acpi device search on acpi bus registered devices
>
> These should replace unnecessary acpi_get_devices invokations
> which ends in a namespace walk.
>
> Signed-off-by: Thomas Renninger <trenn@xxxxxxx>
> CC: Matthew Garrett <mjg@xxxxxxxxxx>
> CC: Len Brown <lenb@xxxxxxxxxx>
> CC: linux-acpi@xxxxxxxxxxxxxxx
> CC: seth.forshee@xxxxxxxxxxxxx
> CC: Azael Avalos <coproscefalo@xxxxxxxxx>
> CC: Henrique de Moraes Holschuh <hmh@xxxxxxxxxx>
>
> ---
> Âdrivers/acpi/scan.c Â| Â 66 ++++++++++++++++++++++++++++++++++++++++++++++++++
> Âinclude/linux/acpi.h | Â Â4 +++
> Â2 files changed, 70 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 8ab80ba..efd97ea 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1606,3 +1606,69 @@ int __init acpi_scan_init(void)
>
> Â Â Â Âreturn result;
> Â}
> +
> +static int acpi_bus_find_cb(struct device *dev, void *data)
> +{
> + Â Â Â struct acpi_device_id *ids = data;
> +
> + Â Â Â if (acpi_match_device_ids(to_acpi_device(dev), ids) == 0)
> + Â Â Â Â Â Â Â return 1;
> + Â Â Â return 0;
> +}
> +
> +/**
> + * acpi_find_devices - find acpi devices of a given HID and execute callback
> + * @ids: The Hardware IDs for matching devices
> + * @match: A callback function which is executed for matching HIDs
> + *
> + * This is the counterpart of acpi_get_devices from ACPICA sources which
> + * should not get executed because it performs a namespace walk.
> + * This function instead iterates only over all ACPI devices found by initially
> + * parsing the ACPI namespace (and thus got added to the ACPI bus).
> + * One difference to acpi_get_devices is that it only finds active devices
> + * which were successfully added to the acpi bus and show up in
> + * /sys/devices/LNXSYSTM:00 and for which an ACPI driver's .add function would
> + * get called.
> + *
> + * ACPI devices with a matching HID or CID are recognized.
> + *
> + * If match returns zero, no further, possibly matching devices are processed.
> + */
> +int acpi_find_devices(struct acpi_device_id *ids, void *data,
> + Â Â Â Â Â Â Â Â Â Â int (*match) (struct acpi_device *dev, void *data))
> +{
> + Â Â Â struct device *hit_dev = NULL;
> +
> + Â Â Â while(1) {
> + Â Â Â Â Â Â Â hit_dev = bus_find_device(&acpi_bus_type, hit_dev, ids,
> + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â acpi_bus_find_cb);
> + Â Â Â Â Â Â Â if (!hit_dev)
> + Â Â Â Â Â Â Â Â Â Â Â break;
> + Â Â Â Â Â Â Â if (!match(to_acpi_device(hit_dev), data))
> + Â Â Â Â Â Â Â Â Â Â Â break;
> + Â Â Â }
> + Â Â Â return 0;
> +}
> +EXPORT_SYMBOL_GPL(acpi_find_devices);
> +
> +/**
> + * acpi_find_device - find an acpi device of a given HID
> + * @ids: The Hardware IDs for matching devices
> + *
> + * Same as acpi_find_devices, but the search will stop on the first found
> + * device and its structure is returned.
> + *
> + * Use this one if you are sure that only 1 ACPI device of a given HID can
> + * exist in ACPI namespace.
> + *
> + * Returns NULL if no device is found.
> + */
> +struct acpi_device *acpi_find_device(struct acpi_device_id *ids)
> +{
> + Â Â Â struct device *dev = bus_find_device(&acpi_bus_type, NULL, ids,
> + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âacpi_bus_find_cb);
> + Â Â Â if (dev)
> + Â Â Â Â Â Â Â return to_acpi_device(dev);
> + Â Â Â return NULL;
> +}
> +EXPORT_SYMBOL_GPL(acpi_find_device);
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 6001b4da..2f9e09e 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -146,6 +146,10 @@ struct acpi_pci_driver {
> Âint acpi_pci_register_driver(struct acpi_pci_driver *driver);
> Âvoid acpi_pci_unregister_driver(struct acpi_pci_driver *driver);
>
> +extern int acpi_find_devices(struct acpi_device_id *ids, void *data,
> + Â Â Â Â Â Â Â Â Â Â Â Â Â Âint (*match) (struct acpi_device *dev, void *data));
> +extern struct acpi_device *acpi_find_device(struct acpi_device_id *ids);
> +
> Âextern int ec_read(u8 addr, u8 *val);
> Âextern int ec_write(u8 addr, u8 val);
> Âextern int ec_transaction(u8 command,
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at Âhttp://vger.kernel.org/majordomo-info.html



-- 
Corentin Chary
http://xf.iksaif.net
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/