1 files changed, 48 insertions, 31 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
index 001be406a3d3..2f8134b2a504 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
@@ -541,48 +541,64 @@ static const struct pci_device_id iwl_hw_card_ids[] = {
 MODULE_DEVICE_TABLE(pci, iwl_hw_card_ids);
 
 #ifdef CONFIG_ACPI
-#define SPL_METHOD              "SPLC"
-#define SPL_DOMAINTYPE_MODULE   BIT(0)
-#define SPL_DOMAINTYPE_WIFI     BIT(1)
-#define SPL_DOMAINTYPE_WIGIG    BIT(2)
-#define SPL_DOMAINTYPE_RFEM     BIT(3)
+#define ACPI_SPLC_METHOD        "SPLC"
+#define ACPI_SPLC_DOMAIN_WIFI   (0x07)
 
-static u64 splx_get_pwr_limit(struct iwl_trans *trans, union acpi_object *splx)
+static u64 splc_get_pwr_limit(struct iwl_trans *trans, union acpi_object *splc)
 {
-        union acpi_object *limits, *domain_type, *power_limit;
-
-        if (splx->type != ACPI_TYPE_PACKAGE ||
-            splx->package.count != 2 ||
-            splx->package.elements[0].type != ACPI_TYPE_INTEGER ||
-            splx->package.elements[0].integer.value != 0) {
-                IWL_ERR(trans, "Unsupported splx structure\n");
+        union acpi_object *data_pkg, *dflt_pwr_limit;
+        int i;
+
+        /* We need at least two elements, one for the revision and one
+         * for the data itself.  Also check that the revision is
+         * supported (currently only revision 0).
+        */
+        if (splc->type != ACPI_TYPE_PACKAGE ||
+            splc->package.count < 2 ||
+            splc->package.elements[0].type != ACPI_TYPE_INTEGER ||
+            splc->package.elements[0].integer.value != 0) {
+                IWL_DEBUG_INFO(trans,
+                               "Unsupported structure returned by the SPLC method.  Ignoring.\n");
                 return 0;
         }
 
-        limits = &splx->package.elements[1];
-        if (limits->type != ACPI_TYPE_PACKAGE ||
-            limits->package.count < 2 ||
-            limits->package.elements[0].type != ACPI_TYPE_INTEGER ||
-            limits->package.elements[1].type != ACPI_TYPE_INTEGER) {
-                IWL_ERR(trans, "Invalid limits element\n");
-                return 0;
+        /* loop through all the packages to find the one for WiFi */
+        for (i = 1; i < splc->package.count; i++) {
+                union acpi_object *domain;
+
+                data_pkg = &splc->package.elements[i];
+
+                /* Skip anything that is not a package with the right
+                 * amount of elements (i.e. at least 2 integers).
+                 */
+                if (data_pkg->type != ACPI_TYPE_PACKAGE ||
+                    data_pkg->package.count < 2 ||
+                    data_pkg->package.elements[0].type != ACPI_TYPE_INTEGER ||
+                    data_pkg->package.elements[1].type != ACPI_TYPE_INTEGER)
+                        continue;
+
+                domain = &data_pkg->package.elements[0];
+                if (domain->integer.value == ACPI_SPLC_DOMAIN_WIFI)
+                        break;
+
+                data_pkg = NULL;
         }
 
-        domain_type = &limits->package.elements[0];
-        power_limit = &limits->package.elements[1];
-        if (!(domain_type->integer.value & SPL_DOMAINTYPE_WIFI)) {
-                IWL_DEBUG_INFO(trans, "WiFi power is not limited\n");
+        if (!data_pkg) {
+                IWL_DEBUG_INFO(trans,
+                               "No element for the WiFi domain returned by the SPLC method.\n");
                 return 0;
         }
 
-        return power_limit->integer.value;
+        dflt_pwr_limit = &data_pkg->package.elements[1];
+        return dflt_pwr_limit->integer.value;
 }
 
 static void set_dflt_pwr_limit(struct iwl_trans *trans, struct pci_dev *pdev)
 {
         acpi_handle pxsx_handle;
         acpi_handle handle;
-        struct acpi_buffer splx = {ACPI_ALLOCATE_BUFFER, NULL};
+        struct acpi_buffer splc = {ACPI_ALLOCATE_BUFFER, NULL};
         acpi_status status;
 
         pxsx_handle = ACPI_HANDLE(&pdev->dev);
@@ -593,23 +609,24 @@ static void set_dflt_pwr_limit(struct iwl_trans *trans, struct pci_dev *pdev)
         }
 
         /* Get the method's handle */
-        status = acpi_get_handle(pxsx_handle, (acpi_string)SPL_METHOD, &handle);
+        status = acpi_get_handle(pxsx_handle, (acpi_string)ACPI_SPLC_METHOD,
+                                 &handle);
         if (ACPI_FAILURE(status)) {
-                IWL_DEBUG_INFO(trans, "SPL method not found\n");
+                IWL_DEBUG_INFO(trans, "SPLC method not found\n");
                 return;
         }
 
         /* Call SPLC with no arguments */
-        status = acpi_evaluate_object(handle, NULL, NULL, &splx);
+        status = acpi_evaluate_object(handle, NULL, NULL, &splc);
         if (ACPI_FAILURE(status)) {
                 IWL_ERR(trans, "SPLC invocation failed (0x%x)\n", status);
                 return;
         }
 
-        trans->dflt_pwr_limit = splx_get_pwr_limit(trans, splx.pointer);
+        trans->dflt_pwr_limit = splc_get_pwr_limit(trans, splc.pointer);
         IWL_DEBUG_INFO(trans, "Default power limit set to %lld\n",
                        trans->dflt_pwr_limit);
-        kfree(splx.pointer);
+        kfree(splc.pointer);
 }
 
 #else /* CONFIG_ACPI */