On Tue, 2008-11-18 at 20:40 +0900, Kenji Kaneshige wrote:
> Andrew Patterson wrote:
> > On Sat, 2008-11-01 at 15:55 +0900, Taku Izumi wrote:
> >> Revert adf411b819adc9fa96e9b3e638c7480d5e71d270.
> >>
> >> The commit adf411b819adc9fa96e9b3e638c7480d5e71d270 was based on the
> >> improper assumption that queried result was not updated when _OSC
> >> support field was changed. But, in fact, queried result is updated
> >> whenever _OSC support field was changed through __acpi_query_osc().
> >> As a result, the commit adf411b819adc9fa96e9b3e638c7480d5e71d270 only
> >> introduced unnecessary additional _OSC evaluation...
> >>
> >> Signed-off-by: Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>
> >> Signed-off-by: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
> >>
> >> ---
> >> drivers/pci/pci-acpi.c | 31 ++++++++++++++++++-------------
> >> 1 file changed, 18 insertions(+), 13 deletions(-)
> >>
> >> Index: 20081031/drivers/pci/pci-acpi.c
> >> ===================================================================
> >> --- 20081031.orig/drivers/pci/pci-acpi.c
> >> +++ 20081031/drivers/pci/pci-acpi.c
> >> @@ -24,13 +24,15 @@ struct acpi_osc_data {
> >> acpi_handle handle;
> >> u32 support_set;
> >> u32 control_set;
> >> + int is_queried;
> >> + u32 query_result;
> >> struct list_head sibiling;
> >> };
> >> static LIST_HEAD(acpi_osc_data_list);
> >>
> >> struct acpi_osc_args {
> >> u32 capbuf[3];
> >> - u32 ctrl_result;
> >> + u32 query_result;
> >> };
> >>
> >> static DEFINE_MUTEX(pci_acpi_lock);
> >> @@ -108,8 +110,9 @@ static acpi_status acpi_run_osc(acpi_han
> >> goto out_kfree;
> >> }
> >> out_success:
> >> - osc_args->ctrl_result =
> >> - *((u32 *)(out_obj->buffer.pointer + 8));
> >> + if (flags & OSC_QUERY_ENABLE)
> >> + osc_args->query_result =
> >> + *((u32 *)(out_obj->buffer.pointer + 8));
> >> status = AE_OK;
> >>
> >> out_kfree:
> >> @@ -117,8 +120,7 @@ out_kfree:
> >> return status;
> >> }
> >>
> >> -static acpi_status __acpi_query_osc(u32 flags, struct acpi_osc_data *osc_data,
> >> - u32 *result)
> >> +static acpi_status __acpi_query_osc(u32 flags, struct acpi_osc_data *osc_data)
> >> {
> >> acpi_status status;
> >> u32 support_set;
> >> @@ -133,7 +135,8 @@ static acpi_status __acpi_query_osc(u32
> >> status = acpi_run_osc(osc_data->handle, &osc_args);
> >> if (ACPI_SUCCESS(status)) {
> >> osc_data->support_set = support_set;
> >> - *result = osc_args.ctrl_result;
> >> + osc_data->query_result = osc_args.query_result;
> >> + osc_data->is_queried = 1;
> >> }
> >>
> >> return status;
> >> @@ -144,7 +147,7 @@ static acpi_status acpi_query_osc(acpi_h
> >> {
> >> acpi_status status;
> >> struct acpi_osc_data *osc_data;
> >> - u32 flags = (unsigned long)context, dummy;
> >> + u32 flags = (unsigned long)context;
> >> acpi_handle tmp;
> >>
> >> status = acpi_get_handle(handle, "_OSC", &tmp);
> >> @@ -158,7 +161,7 @@ static acpi_status acpi_query_osc(acpi_h
> >> goto out;
> >> }
> >>
> >> - __acpi_query_osc(flags, osc_data, &dummy);
> >> + __acpi_query_osc(flags, osc_data);
> >> out:
> >> mutex_unlock(&pci_acpi_lock);
> >> return AE_OK;
> >> @@ -192,7 +195,7 @@ acpi_status __pci_osc_support_set(u32 fl
> >> acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
> >> {
> >> acpi_status status;
> >> - u32 ctrlset, control_set, result;
> >> + u32 ctrlset, control_set;
> >> acpi_handle tmp;
> >> struct acpi_osc_data *osc_data;
> >> struct acpi_osc_args osc_args;
> >> @@ -215,11 +218,13 @@ acpi_status pci_osc_control_set(acpi_han
> >> goto out;
> >> }
> >>
> >> - status = __acpi_query_osc(osc_data->support_set, osc_data, &result);
> >> - if (ACPI_FAILURE(status))
> >> - goto out;
> >> + if (!osc_data->is_queried) {
> >> + status = __acpi_query_osc(osc_data->support_set, osc_data);
> >> + if (ACPI_FAILURE(status))
> >> + goto out;
> >> + }
> >>
> >> - if ((result & ctrlset) != ctrlset) {
> >> + if ((osc_data->query_result & ctrlset) != ctrlset) {
> >> status = AE_SUPPORT;
> >> goto out;
> >> }
> >>
> >
> > The latest code in the pci-2.6/linux-next branch runs __acpi_query_osc()
> > in acpi_pci_root_add(). This happens before any calls to
> > pci_osc_control_set(), so this patch/revert should no longer be
> > necessary.
> >
>
> Though I might be misunderstanding, I think you mean that we should
> modify pci_osc_control_set() not to call __acpi_query_osc()
Yes.
> in any
> case rather than applying this patch (reverting the commit
> adf411b819adc9fa96e9b3e638c7480d5e71d270). Correct?
>
> I think we should apply this patch first, and then making another
> patch to modify pci_osc_control_set() not to call __acpi_query_osc()
> because current pci_acpi_osc_support() can fail with -ENOMEM.
Good point. This patch will need to be respun for pci-2.6/linux-next.
Note that the original patch did not remove the no longer needed "dummy"
variable in __acpi_query_osc().
> In
> this case, pci_osc_control_set() must query control. Maybe we need to
> modify some data structures (acpi_osc_data, acpi_pci_root, etc.) to
> prevent -ENOMEM when we modify pci_osc_control_set() not to call
> __acpi_query_osc().
I think Willy's plan was to move this structure into acpi_pci_root
structure which would eliminate the -ENOMEM problem. We can remove the
call then.
>
> Thanks,
> Kenji Kaneshige
>
>
--
Andrew Patterson
Hewlett-Packard
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