2013/5/21 <jeff.wu@xxxxxxx>:
> 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.
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
>
>
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--
Best regards
Tianyu Lan
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