Re: [PATCH 1/8] ACPI / PCI: Introduce acpi_pci_osc_control_query()

On Tuesday, August 03, 2010, Kenji Kaneshige wrote:

(2010/08/03 6:53), Rafael J. Wysocki wrote:

quoted

From: Rafael J. Wysocki<redacted>

<snip.>

quoted

+	mutex_lock(&osc_lock);
+	status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask);
+	mutex_unlock(&osc_lock);
+

One more comment here.

I think we can skip acpi_pci_query_osc() if all of queried controls are
already granted to OS. Please see below

	mutex_lock(&osc_lock);
	if ((root->osc_control_set & *ctrl_mask) == *ctrl_mask) {
		*ctrl_mask = root->osc_control_set;
		goto out;
	}
	status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask);
	mutex_unlock(&osc_lock);
out:

Well I guess you mean:

 	mutex_lock(&osc_lock);
 	if ((root->osc_control_set & *ctrl_mask) != *ctrl_mask) 
 		status = acpi_pci_query_osc(root, root->osc_support_set, ctrl_mask);
 	mutex_unlock(&osc_lock);

Otherwise we would return with the mutex held. :-)

Thanks,
Rafael