/* 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) {
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);
}
}
}
/* NOTE in the active case, we do not need to do anything further,
* when an EP goes active and needs credits, HTC will call into
* our distribution function using a reason code of HTC_CREDIT_DIST_SEEK_CREDITS */
pCurEpDist = pCurEpDist->pNext;
}
}
/* redistribute credits based on activity change */
static void RedistributeCredits(struct common_credit_state_info *pCredInfo,
struct htc_endpoint_credit_dist *pEPDistList)
{
struct 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);
}
}
}
/* NOTE in the active case, we do not need to do anything further,
* when an EP goes active and needs credits, HTC will call into
* our distribution function using a reason code of HTC_CREDIT_DIST_SEEK_CREDITS */
pCurEpDist = pCurEpDist->pNext;
}
}
/* default credit distribution callback
* This callback is invoked whenever endpoints require credit distributions.
* A lock is held while this function is invoked, this function shall NOT block.
* The pEPDistList is a list of distribution structures in prioritized order as
* defined by the call to the HTCSetCreditDistribution() api.
*
*/
static void ar6000_credit_distribute(void *Context,
HTC_ENDPOINT_CREDIT_DIST *pEPDistList,
HTC_CREDIT_DIST_REASON Reason)
{
HTC_ENDPOINT_CREDIT_DIST *pCurEpDist;
COMMON_CREDIT_STATE_INFO *pCredInfo = (COMMON_CREDIT_STATE_INFO *)Context;
switch (Reason) {
case HTC_CREDIT_DIST_SEND_COMPLETE :
pCurEpDist = pEPDistList;
/* we are given the start of the endpoint distribution list.
* There may be one or more endpoints to service.
* Run through the list and distribute credits */
while (pCurEpDist != NULL) {
if (pCurEpDist->TxCreditsToDist > 0) {
/* return the credits back to the endpoint */
pCurEpDist->TxCredits += pCurEpDist->TxCreditsToDist;
/* always zero out when we are done */
pCurEpDist->TxCreditsToDist = 0;
if (pCurEpDist->TxCredits > pCurEpDist->TxCreditsAssigned) {
/* reduce to the assigned limit, previous credit reductions
* could have caused the limit to change */
ReduceCredits(pCredInfo, pCurEpDist, pCurEpDist->TxCreditsAssigned);
}
if (pCurEpDist->TxCredits > pCurEpDist->TxCreditsNorm) {
/* oversubscribed endpoints need to reduce back to normal */
ReduceCredits(pCredInfo, pCurEpDist, pCurEpDist->TxCreditsNorm);
}
if (!IS_EP_ACTIVE(pCurEpDist)) {
/* endpoint is inactive, now check for messages waiting for credits */
if (pCurEpDist->TxQueueDepth == 0) {
/* EP is inactive and there are no pending messages,
* reduce credits back to zero to recover credits */
ReduceCredits(pCredInfo, pCurEpDist, 0);
}
}
}
pCurEpDist = pCurEpDist->pNext;
}
break;
case HTC_CREDIT_DIST_ACTIVITY_CHANGE :
RedistributeCredits(pCredInfo,pEPDistList);
break;
case HTC_CREDIT_DIST_SEEK_CREDITS :
SeekCredits(pCredInfo,pEPDistList);
break;
case HTC_DUMP_CREDIT_STATE :
AR_DEBUG_PRINTF(ATH_DEBUG_ERR, ("Credit Distribution, total : %d, free : %d\n",
pCredInfo->TotalAvailableCredits, pCredInfo->CurrentFreeCredits));
break;
default:
break;
}
/* sanity checks done after each distribution action */
A_ASSERT(pCredInfo->CurrentFreeCredits <= pCredInfo->TotalAvailableCredits);
A_ASSERT(pCredInfo->CurrentFreeCredits >= 0);
}
