ACPI: Early _PDC tweaks

As requested by Len, a few more improvements in how we handle the early _PDC path.

Allow platforms not listed in the DMI table to opt-in for early _PDC with a kernel command line param.

If we do evaluate _PDC early, remember that fact and do not evaluate it a second time when the ACPI processor driver loads.

/ac

---

Alex Chiang (2):
ACPI: processor: add kernel command line support for early _PDC eval
ACPI: processor: only evaluate _PDC once per processor

 Documentation/kernel-parameters.txt |    4 ++++
 drivers/acpi/processor_pdc.c        |   14 ++++++++++++++
 2 files changed, 18 insertions(+), 0 deletions(-)

Allow platforms not listed in DMI table to opt-in and evaluate _PDC early.

---

 Documentation/kernel-parameters.txt |    4 ++++
 drivers/acpi/processor_pdc.c        |    7 +++++++
 2 files changed, 11 insertions(+), 0 deletions(-)

index 736d456..826b6e1 100644
@@ -199,6 +199,10 @@ and is between 256 and 4096 characters. It is defined in the file
 			acpi_display_output=video
 			See above.
 
+	acpi_early_pdc_eval	[HW,ACPI] Evaluate processor _PDC methods
+				early. Needed on some platforms to properly
+				initialize the EC.
+
 	acpi_irq_balance [HW,ACPI]
 			ACPI will balance active IRQs
 			default in APIC mode

index f336437..2944e7d 100644
@@ -151,6 +151,13 @@ static int set_early_pdc_optin(const struct dmi_system_id *id)
 	return 0;
 }
 
+static int param_early_pdc_optin(char *s)
+{
+	early_pdc_optin = 1;
+	return 1;
+}
+__setup("acpi_early_pdc_eval", param_early_pdc_optin);
+
 static struct dmi_system_id __cpuinitdata early_pdc_optin_table[] = {
 	{
 	set_early_pdc_optin, "HP Envy", {

applied

thanks,
Len Brown, Intel Open Source Technology Center

If we evaluate _PDC in the early path, we do not want to evaluate it again when the processor driver is loaded.

---

 drivers/acpi/processor_pdc.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

index 2944e7d..54f0214 100644
@@ -125,6 +125,8 @@ acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
 	return status;
 }
 
+static int early_pdc_done;
+
 void acpi_processor_set_pdc(acpi_handle handle)
 {
 	struct acpi_object_list *obj_list;

@@ -132,6 +134,9 @@ void acpi_processor_set_pdc(acpi_handle handle)
 	if (arch_has_acpi_pdc() == false)
 		return;
 
+	if (early_pdc_done)
+		return;
+
 	obj_list = acpi_processor_alloc_pdc();
 	if (!obj_list)
 		return;

@@ -199,4 +204,6 @@ void acpi_early_processor_set_pdc(void)
 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 			    ACPI_UINT32_MAX,
 			    early_init_pdc, NULL, NULL, NULL);
+
+	early_pdc_done = 1;
 }

applied

thanks,
Len Brown, Intel Open Source Technology Center