ath6kl: Bringing in the upstream version

chromeos/drivers/ath6kl/miscdrv/credit_dist.c

 //------------------------------------------------------------------------------
 // <copyright file="credit_dist.c" company="Atheros">
-//    Copyright (c) 2004-2008 Atheros Corporation.  All rights reserved.
+//    Copyright (c) 2004-2010 Atheros Corporation.  All rights reserved.
 // 
-// This program is free software; you can redistribute it and/or modify
-// it under the terms of the GNU General Public License version 2 as
-// published by the Free Software Foundation;
 //
-// Software distributed under the License is distributed on an "AS
-// IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
-// implied. See the License for the specific language governing
-// rights and limitations under the License.
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 //
 //
 //------------------------------------------------------------------------------
 //==============================================================================
 // Author(s): ="Atheros"
 //==============================================================================
 
 #include "a_config.h"
 #include "athdefs.h"
 #include "a_types.h"
 #include "a_osapi.h"
 #define ATH_MODULE_NAME misc
 #include "a_debug.h"
 #include "htc_api.h"
 #include "common_drv.h"
 
 /********* CREDIT DISTRIBUTION FUNCTIONS ******************************************/
 
 #define NO_VO_SERVICE 1 /* currently WMI only uses 3 data streams, so we leave VO service inactive */
+#define CONFIG_GIVE_LOW_PRIORITY_STREAMS_MIN_CREDITS 1
 
 #ifdef NO_VO_SERVICE
 #define DATA_SVCS_USED 3
 #else
 #define DATA_SVCS_USED 4
 #endif
 
 static void RedistributeCredits(COMMON_CREDIT_STATE_INFO *pCredInfo,
                                 HTC_ENDPOINT_CREDIT_DIST *pEPDistList);
 
@@ skipping 45 matching lines @@
     pCredInfo->TotalAvailableCredits = TotalCredits;
 
     pCurEpDist = pEPList;
 
         /* run through the list and initialize */
     while (pCurEpDist != NULL) {
 
             /* set minimums for each endpoint */
         pCurEpDist->TxCreditsMin = pCurEpDist->TxCreditsPerMaxMsg;
 
+#ifdef CONFIG_GIVE_LOW_PRIORITY_STREAMS_MIN_CREDITS
+ 
+      if (TotalCredits > 4)
+      {
+          if ((pCurEpDist->ServiceID == WMI_DATA_BK_SVC)  || (pCurEpDist->ServiceID == WMI_DATA_BE_SVC)){
+                    /* assign at least min credits to lower than VO priority services */
+                GiveCredits(pCredInfo,pCurEpDist,pCurEpDist->TxCreditsMin);
+                    /* force active */
+                SET_EP_ACTIVE(pCurEpDist);
+          }
+      }
+ 
+#endif
+
         if (pCurEpDist->ServiceID == WMI_CONTROL_SVC) {
                 /* give control service some credits */
             GiveCredits(pCredInfo,pCurEpDist,pCurEpDist->TxCreditsMin);
                 /* control service is always marked active, it never goes inactive EVER */
             SET_EP_ACTIVE(pCurEpDist);
         } else if (pCurEpDist->ServiceID == WMI_DATA_BK_SVC) {
                 /* this is the lowest priority data endpoint, save this off for easy access */
             pCredInfo->pLowestPriEpDist = pCurEpDist;
         }
 
@@ skipping 118 matching lines @@
 
 /* redistribute credits based on activity change */
 static void RedistributeCredits(COMMON_CREDIT_STATE_INFO *pCredInfo,
                                 HTC_ENDPOINT_CREDIT_DIST *pEPDistList)
 {
     HTC_ENDPOINT_CREDIT_DIST *pCurEpDist = pEPDistList;
 
         /* walk through the list and remove credits from inactive endpoints */
     while (pCurEpDist != NULL) {
 
+#ifdef CONFIG_GIVE_LOW_PRIORITY_STREAMS_MIN_CREDITS
+
+        if ((pCurEpDist->ServiceID == WMI_DATA_BK_SVC)  || (pCurEpDist->ServiceID == WMI_DATA_BE_SVC)) {
+              /* force low priority streams to always be active to retain their minimum credit distribution */
+             SET_EP_ACTIVE(pCurEpDist);
+        }
+#endif
+
         if (pCurEpDist->ServiceID != WMI_CONTROL_SVC) {
             if (!IS_EP_ACTIVE(pCurEpDist)) {
                 if (pCurEpDist->TxQueueDepth == 0) {
                         /* EP is inactive and there are no pending messages, reduce credits back to zero */
                     ReduceCredits(pCredInfo, pCurEpDist, 0);
                 } else {
                         /* we cannot zero the credits assigned to this EP, but to keep
                          * the credits available for these leftover packets, reduce to
                          * a minimum */
                     ReduceCredits(pCredInfo, pCurEpDist, pCurEpDist->TxCreditsMin);
@@ skipping 20 matching lines @@
 
     do {
 
         if (pEPDist->ServiceID == WMI_CONTROL_SVC) {
                 /* we never oversubscribe on the control service, this is not
                  * a high performance path and the target never holds onto control
                  * credits for too long */
             break;
         }
 
+#ifdef CONFIG_GIVE_LOW_PRIORITY_STREAMS_MIN_CREDITS
+        if (pEPDist->ServiceID == WMI_DATA_VI_SVC) {
+            if ((pEPDist->TxCreditsAssigned >= pEPDist->TxCreditsNorm)) {
+                 /* limit VI service from oversubscribing */
+                 break;
+            }
+        }
+ 
+        if (pEPDist->ServiceID == WMI_DATA_VO_SVC) {
+            if ((pEPDist->TxCreditsAssigned >= pEPDist->TxCreditsNorm)) {
+                 /* limit VO service from oversubscribing */
+                break;
+            }
+        }
+#else
         if (pEPDist->ServiceID == WMI_DATA_VI_SVC) {
             if ((pEPDist->TxCreditsAssigned >= pEPDist->TxCreditsNorm) ||
                 (pCredInfo->CurrentFreeCredits <= pEPDist->TxCreditsPerMaxMsg)) {
                  /* limit VI service from oversubscribing */
                  /* at least one free credit will not be used by VI */
                  break;
             }
         }
  
         if (pEPDist->ServiceID == WMI_DATA_VO_SVC) {
             if ((pEPDist->TxCreditsAssigned >= pEPDist->TxCreditsNorm) ||
                 (pCredInfo->CurrentFreeCredits <= pEPDist->TxCreditsPerMaxMsg)) {
                  /* limit VO service from oversubscribing */
                  /* at least one free credit will not be used by VO */
                 break;
             }
         }
+#endif
 
         /* for all other services, we follow a simple algorithm of
          * 1. checking the free pool for credits
          * 2. checking lower priority endpoints for credits to take */
 
             /* give what we can */
         credits = min(pCredInfo->CurrentFreeCredits,pEPDist->TxCreditsSeek);
 
         if (credits >= pEPDist->TxCreditsSeek) {
                 /* we found some to fullfill the seek request */
@@ skipping 64 matching lines @@
     HTCSetCreditDistribution(HTCHandle,
                              pCredInfo,
                              ar6000_credit_distribute,
                              ar6000_credit_init,
                              servicepriority,
                              5);
 
     return A_OK;
 }