1 files changed, 107 insertions, 20 deletions

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index 6ad0e77df9b3..834c2ceff1aa 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -68,6 +68,10 @@ static struct acpi_driver acpi_pci_link_driver = {
                         },
 };
 
+/*
+ * If a link is initialized, we never change its active and initialized
+ * later even the link is disable. Instead, we just repick the active irq
+ */
 struct acpi_pci_link_irq {
         u8                      active;                 /* Current IRQ */
         u8                      edge_level;             /* All IRQs */
@@ -76,8 +80,7 @@ struct acpi_pci_link_irq {
         u8                      possible_count;
         u8                      possible[ACPI_PCI_LINK_MAX_POSSIBLE];
         u8                      initialized:1;
-        u8                      suspend_resume:1;
-        u8                      reserved:6;
+        u8                      reserved:7;
 };
 
 struct acpi_pci_link {
@@ -85,12 +88,14 @@ struct acpi_pci_link {
         struct acpi_device      *device;
         acpi_handle             handle;
         struct acpi_pci_link_irq irq;
+        int                     refcnt;
 };
 
 static struct {
         int                     count;
         struct list_head        entries;
 }                               acpi_link;
+DECLARE_MUTEX(acpi_link_lock);
 
 
 /* --------------------------------------------------------------------------
@@ -532,12 +537,12 @@ static int acpi_pci_link_allocate(
 
         ACPI_FUNCTION_TRACE("acpi_pci_link_allocate");
 
-        if (link->irq.suspend_resume) {
-                acpi_pci_link_set(link, link->irq.active);
-                link->irq.suspend_resume = 0;
-        }
-        if (link->irq.initialized)
+        if (link->irq.initialized) {
+                if (link->refcnt == 0)
+                        /* This means the link is disabled but initialized */
+                        acpi_pci_link_set(link, link->irq.active);
                 return_VALUE(0);
+        }
 
         /*
          * search for active IRQ in list of possible IRQs.
@@ -596,13 +601,13 @@ static int acpi_pci_link_allocate(
 }
 
 /*
- * acpi_pci_link_get_irq
+ * acpi_pci_link_allocate_irq
  * success: return IRQ >= 0
  * failure: return -1
  */
 
 int
-acpi_pci_link_get_irq (
+acpi_pci_link_allocate_irq (
         acpi_handle             handle,
         int                     index,
         int                     *edge_level,
@@ -613,7 +618,7 @@ acpi_pci_link_get_irq (
         struct acpi_device      *device = NULL;
         struct acpi_pci_link    *link = NULL;
 
-        ACPI_FUNCTION_TRACE("acpi_pci_link_get_irq");
+        ACPI_FUNCTION_TRACE("acpi_pci_link_allocate_irq");
 
         result = acpi_bus_get_device(handle, &device);
         if (result) {
@@ -633,21 +638,81 @@ acpi_pci_link_get_irq (
                 return_VALUE(-1);
         }
 
-        if (acpi_pci_link_allocate(link))
+        down(&acpi_link_lock);
+        if (acpi_pci_link_allocate(link)) {
+                up(&acpi_link_lock);
                 return_VALUE(-1);
+        }
            
         if (!link->irq.active) {
+                up(&acpi_link_lock);
                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link active IRQ is 0!\n"));
                 return_VALUE(-1);
         }
+        link->refcnt ++;
+        up(&acpi_link_lock);
 
         if (edge_level) *edge_level = link->irq.edge_level;
         if (active_high_low) *active_high_low = link->irq.active_high_low;
         if (name) *name = acpi_device_bid(link->device);
+        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                "Link %s is referenced\n", acpi_device_bid(link->device)));
         return_VALUE(link->irq.active);
 }
 
+/*
+ * We don't change link's irq information here.  After it is reenabled, we
+ * continue use the info
+ */
+int
+acpi_pci_link_free_irq(acpi_handle handle)
+{
+        struct acpi_device      *device = NULL;
+        struct acpi_pci_link    *link = NULL;
+        acpi_status             result;
+
+        ACPI_FUNCTION_TRACE("acpi_pci_link_free_irq");
+
+        result = acpi_bus_get_device(handle, &device);
+        if (result) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link device\n"));
+                return_VALUE(-1);
+        }
+
+        link = (struct acpi_pci_link *) acpi_driver_data(device);
+        if (!link) {
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
+                return_VALUE(-1);
+        }
+
+        down(&acpi_link_lock);
+        if (!link->irq.initialized) {
+                up(&acpi_link_lock);
+                ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Link isn't initialized\n"));
+                return_VALUE(-1);
+        }
 
+#ifdef  FUTURE_USE
+        /*
+         * The Link reference count allows us to _DISable an unused link
+         * and suspend time, and set it again  on resume.
+         * However, 2.6.12 still has irq_router.resume
+         * which blindly restores the link state.
+         * So we disable the reference count method
+         * to prevent duplicate acpi_pci_link_set()
+         * which would harm some systems
+         */
+        link->refcnt --;
+#endif
+        ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+                "Link %s is dereferenced\n", acpi_device_bid(link->device)));
+
+        if (link->refcnt == 0) {
+                acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
+        }
+        up(&acpi_link_lock);
+        return_VALUE(link->irq.active);
+}
 /* --------------------------------------------------------------------------
                                  Driver Interface
    -------------------------------------------------------------------------- */
@@ -677,6 +742,7 @@ acpi_pci_link_add (
         strcpy(acpi_device_class(device), ACPI_PCI_LINK_CLASS);
         acpi_driver_data(device) = link;
 
+        down(&acpi_link_lock);
         result = acpi_pci_link_get_possible(link);
         if (result)
                 goto end;
@@ -712,6 +778,7 @@ acpi_pci_link_add (
 end:
         /* disable all links -- to be activated on use */
         acpi_ut_evaluate_object(link->handle, "_DIS", 0, NULL);
+        up(&acpi_link_lock);
 
         if (result)
                 kfree(link);
@@ -720,24 +787,42 @@ end:
 }
 
 static int
-irqrouter_suspend(
-        struct sys_device *dev,
-        u32     state)
+acpi_pci_link_resume(
+        struct acpi_pci_link *link)
+{
+        ACPI_FUNCTION_TRACE("acpi_pci_link_resume");
+
+        if (link->refcnt && link->irq.active && link->irq.initialized)
+                return_VALUE(acpi_pci_link_set(link, link->irq.active));
+        else
+                return_VALUE(0);
+}
+
+/*
+ * FIXME: this is a workaround to avoid nasty warning.  It will be removed
+ * after every device calls pci_disable_device in .resume.
+ */
+int acpi_in_resume;
+static int
+irqrouter_resume(
+        struct sys_device *dev)
 {
         struct list_head        *node = NULL;
         struct acpi_pci_link    *link = NULL;
 
-        ACPI_FUNCTION_TRACE("irqrouter_suspend");
+        ACPI_FUNCTION_TRACE("irqrouter_resume");
 
+        acpi_in_resume = 1;
         list_for_each(node, &acpi_link.entries) {
                 link = list_entry(node, struct acpi_pci_link, node);
                 if (!link) {
-                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid link context\n"));
+                        ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
+                                "Invalid link context\n"));
                         continue;
                 }
-                if (link->irq.active && link->irq.initialized)
-                        link->irq.suspend_resume = 1;
+                acpi_pci_link_resume(link);
         }
+        acpi_in_resume = 0;
         return_VALUE(0);
 }
 
@@ -756,8 +841,9 @@ acpi_pci_link_remove (
 
         link = (struct acpi_pci_link *) acpi_driver_data(device);
 
-        /* TBD: Acquire/release lock */
+        down(&acpi_link_lock);
         list_del(&link->node);
+        up(&acpi_link_lock);
 
         kfree(link);
 
@@ -849,9 +935,10 @@ int __init acpi_irq_balance_set(char *str)
 __setup("acpi_irq_balance", acpi_irq_balance_set);
 
 
+/* FIXME: we will remove this interface after all drivers call pci_disable_device */
 static struct sysdev_class irqrouter_sysdev_class = {
         set_kset_name("irqrouter"),
-        .suspend = irqrouter_suspend,
+        .resume = irqrouter_resume,
 };