2013/5/28 Rafael J. Wysocki <rjw@xxxxxxx>: > On Tuesday, May 28, 2013 11:22:17 AM jeff.wu@xxxxxxx wrote: >> From: Jeff Wu <zlinuxkernel@xxxxxxxxx> >> >> v2: >> 1).If it's only one matching device, whether the deivce status is enabled or disabled, >> do_acpi_find_child() return its' handle >> 2).If it's more than one matching devices, do_acpi_find_child() return the first >> enabled device handle >> The idea mail thread: >> http://wwww.spinics.net/lists/linux-acpi/msg43481.html > > The information what's changed in v2 with respect to v1 is rather not > interesting to the future readers of the changelog, so can you please rearrange > it as one comprehensive description of the patch? Ok, i will rearrange it and send out the patch. Thanks Jeff wu > > The patch itself looks good to me. That‘s great. > > Thanks, > Rafael > > >> v1: >> 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 | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c >> index 40a84cc..51ca764 100644 >> --- a/drivers/acpi/glue.c >> +++ b/drivers/acpi/glue.c >> @@ -81,13 +81,15 @@ 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; >> + unsigned long long addr, sta; >> acpi_status status; >> >> status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr); >> if (ACPI_SUCCESS(status) && addr == *((u64 *)addr_p)) { >> *ret_p = handle; >> - return AE_CTRL_TERMINATE; >> + status = acpi_bus_get_status_handle(handle, &sta); >> + if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_ENABLED)) >> + return AE_CTRL_TERMINATE; >> } >> return AE_OK; >> } >> > -- > I speak only for myself. > Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
