2013/5/23 Rafael J. Wysocki <rjw@xxxxxxx>:
> On Wednesday, May 22, 2013 03:42:04 PM Jeff Wu wrote:
>> 2013/5/22 Lan Tianyu <lantianyu1986@xxxxxxxxx>:
>> > 2013/5/22 Jeff Wu <zlinuxkernel@xxxxxxxxx>:
>> >> 2013/5/21 Lan Tianyu <lantianyu1986@xxxxxxxxx>:
>> >>>> From: Jeff Wu <zlinuxkernel@xxxxxxxxx>
>> >>>>
>> >>>> Once do_acpi_find_child() found the first matching handle, it makes the acpi_get_child()
>> >>>> loop stop and return the matching handle. But, at some of the platforms, a "_ADR" is
>> >>>> with the multiple devices, and if one is enabled, the others will be disabled.
>> >>>> Just like a case:
>> >>>> Address : 0x1FFFF ; handle : SB_PCI0.SATA.DEV0
>> >>>> Address : 0x1FFFF ; handle : SB_PCI0.SATA.DEV1
>> >>>> Address : 0x1FFFF ; handle : SB_PCI0.SATA.DEV2
>> >>>>
>> >>>> If DEV0 and DEV1 are disabled and DEV2 is enabled, the target is to get DEV2 handle, but
>> >>>> actually it always return the first disabled device DEV0 handle. So add a _STA evaluating
>> >>>> at do_acpi_find_child() to check the device status. If the object exists, but it is disabled,
>> >>>> acpi_get_child() will continue looping to get the correct handle that the object exists and
>> >>>> is enabled.
>> >>>>
>> >>>>
>> >>>> Signed-off-by: Jeff Wu <zlinuxkernel@xxxxxxxxx>
>> >>>> ---
>> >>>> drivers/acpi/glue.c | 5 ++++-
>> >>>> 1 file changed, 4 insertions(+), 1 deletion(-)
>> >>>>
>> >>>> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
>> >>>> index 40a84cc..ace6c2e 100644
>> >>>> --- a/drivers/acpi/glue.c
>> >>>> +++ b/drivers/acpi/glue.c
>> >>>> @@ -81,11 +81,14 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
>> >>>> static acpi_status do_acpi_find_child(acpi_handle handle, u32 lvl_not_used,
>> >>>> void *addr_p, void **ret_p)
>> >>>> {
>> >>>> - unsigned long long addr;
>> >>>> acpi_status status;
>> >>>> + unsigned long long addr = 0, sta = 0;
>> >>>>
>> >>>> status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
>> >>>> if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) {
>> >>>> + status = acpi_bus_get_status_handle(handle, &sta);
>> >>>> + if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_ENABLED))
>> >>>> + return AE_CTRL_DEPTH;
>> >>> Will this affect other devices? Since the device maybe disabled during
>> >>> do binding with ACPI.
>> >>> After some operations, the device would be enabled.
>> >> At our platforms, DEV1 use for win8,DEV2 use for win7,DEV1 use for Linux.
>> >> If these devices are disabled when do init, they will always be
>> >> disabled ,so, work fine.
>> >>
>> >> At some of the platforms, the devices may be disabled during do the
>> >> first binding ,if their status are changed,do they not do re-binding ?
>> > Currently, the glue binding operation takes place when the device is
>> > created. In my mind, there is no re-binding operation after the device being
>> > created, Unless the device being removed and created again.
>> Thank you very much.
>> So, as your suggestion, it is a better solution to add a new function
>> for the same _ADR devices,
>
> I don't really think this is a good idea, because then it won't be clear when
> to use which version.
>
> Your patch kind of makes sense (although we don't need to initialize both
> local variables to 0), but the Tianyu's concern is valid in principle either.
>
> Perhaps it would be better to make do_acpi_find_child() return the disabled
> device if its the only one matching or the first enabled matching device
> otherwise?
Hi Rafael,
Thanks, i will try it , if it is ok, i will send out the patch.
>
> Rafael
>
>
>> >>> Hi Rafael:
>> >>> How about add a new function
>> >>> "acpi_get_children_with_same_addr" to return a list
>> >>> which contains all these child devices with same _ADR.And then do some
>> >>> special check in the specific
>> >>> bus glue callback. Since these cases are no common.
>> >>>
>> >>>> *ret_p = handle;
>> >>>> return AE_CTRL_TERMINATE;
>> >>>> }
>> >>>> --
>> >>>> 1.8.1.2
>> >>>>
>> >>>>
>> >>>> --
>> >>>> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
>> >>>> the body of a message to majordomo@xxxxxxxxxxxxxxx
>> >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>> Best regards
>> >>> Tianyu Lan
>> >
>> >
>> >
>> > --
>> > Best regards
>> > Tianyu Lan
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
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> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
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