Added small workaround for (possible) bug in VMS secondary bootstrap; improved reset behavior.

4.3bsd still panics during uda bringup.

10.01_base/2_src/arm/unibusadapter.cpp

@@ -175,13 +175,9 @@ void unibusadapter_c::worker_init_event() {
 			device->on_init_changed();
 		}
 
-        INFO("clearing due to INIT empty %d", _irqRequests.empty());
 
  	// Clear bus request queues
-        pthread_mutex_lock(&_busWorker_mutex);
-        while (!_dmaRequests.empty()) _dmaRequests.pop();
-        while (!_irqRequests.empty()) _irqRequests.pop();
-        pthread_mutex_unlock(&_busWorker_mutex);
+        rundown_bus_requests();
 }
 
 void unibusadapter_c::worker_power_event() {
@@ -195,13 +191,8 @@ void unibusadapter_c::worker_power_event() {
 			device->on_power_changed();
 		}
 
-        INFO("clearing due to power empty %d", _irqRequests.empty());
-
 	// Clear bus request queues
-	pthread_mutex_lock(&_busWorker_mutex);
- 	while (!_dmaRequests.empty()) _dmaRequests.pop();
-        while (!_irqRequests.empty()) _irqRequests.pop();
-        pthread_mutex_unlock(&_busWorker_mutex);
+	rundown_bus_requests();
 }
 
 // process DATI/DATO access to active device registers
@@ -625,16 +616,6 @@ void unibusadapter_c::dma_worker()
 		// Sanity check: Should be no active DMA or interrupt requests on the PRU.
 		assert (!request_DMA_active(nullptr) && !request_INTR_active(nullptr));
 
-                /*
-		// If there's an IRQ still active, wait for it to finish.
-		// TODO: find a way to avoid having to do this.
-		timeout_c timer;
-		while (request_INTR_active(nullptr))
-		{
-                        INFO("intr active");
-			timer.wait_us(50);
-		} */
-
 		if (dmaReq)
 		{
 			// We do the DMA transfer in chunks so we can handle arbitrary buffer sizes.
@@ -693,14 +674,9 @@ void unibusadapter_c::dma_worker()
 			dmaReq->SetUnibusEndAddr(mailbox->dma.cur_addr);
 			dmaReq->SetSuccess(mailbox->dma.cur_status == DMA_STATE_READY);
 
-			if(dmaReq->GetUnibusAddr() + dmaReq->GetWordCount() * 2 != mailbox->dma.cur_addr + 2)
+			assert(dmaReq->GetUnibusAddr() + dmaReq->GetWordCount() * 2 == 
+				mailbox->dma.cur_addr + 2);
 
-			{
-				FATAL("PRU end addr 0x%x, expected 0x%x",
-					mailbox->dma.cur_addr + 2,
-					dmaReq->GetUnibusAddr() + dmaReq->GetWordCount() * 2);
-			}
-		
 			//
 			// Signal that the request is complete.
 			//
@@ -759,6 +735,33 @@ void unibusadapter_c::dma_worker()
 	}
 }
 
+void unibusadapter_c::rundown_bus_requests()
+{
+	//
+	// Cancel all pending DMA and IRQ requests, freeing threads waiting
+	// on completion.
+	//
+	pthread_mutex_lock(&_busWorker_mutex);
+        while (!_dmaRequests.empty()) 
+	{
+		dma_request_c* dmaReq = _dmaRequests.front();
+		dmaReq->SetSuccess(false);
+		dmaReq->SetComplete();
+		pthread_cond_signal(&_requestFinished_cond);
+		_dmaRequests.pop();
+	}
+        while (!_irqRequests.empty())
+	{
+		irq_request_c* irqReq = _irqRequests.front();
+		irqReq->SetComplete();
+		pthread_cond_signal(&_requestFinished_cond);
+		_irqRequests.pop();
+	}
+        pthread_mutex_unlock(&_busWorker_mutex);
+
+}
+
+
 void unibusadapter_c::request_INTR(uint32_t level, uint32_t vector) {
         //
         // Acquire bus mutex; append new request to queue.

10.01_base/2_src/arm/unibusadapter.hpp

@@ -124,6 +124,7 @@ public:
 	bool request_DMA(uint8_t unibus_control, uint32_t unibus_addr,
 			uint16_t *buffer, uint32_t wordcount);
 	void request_INTR(uint32_t level, uint32_t vector);
+        void rundown_bus_requests(void);
 
 	void print_shared_register_map(void);
 

10.02_devices/2_src/mscp_server.cpp

@@ -122,9 +122,6 @@ mscp_server::Poll(void)
 
         pthread_mutex_unlock(&polling_mutex);
     
-        // timer.wait_us(100);
-
-
         if (_abort_polling)
         {
             break;
@@ -262,6 +259,14 @@ mscp_server::Poll(void)
                 FATAL("no room at the inn.");
             }
 
+            //
+            // This delay works around an issue in the VMS bootstrap -- unsure of the 
+            // exact cause, it appears to be a race condition exacerbated by the speed
+            // at which we're able to process commands in the ring buffer (we are much
+            // faster than any real MSCP device ever was.)
+            // This is likely a hack, we may be papering over a bug somewhere.
+            // 
+            timer.wait_us(100);
  
             //
             // Go around and pick up the next one.

10.02_devices/2_src/uda.cpp

@@ -78,10 +78,7 @@ uda_c::~uda_c()
 
 void uda_c::Reset(void)
 {
-    DEBUG("UDA reset");
-
-    _sa = 0;
-    update_SA();
+    INFO("UDA reset");
 
     _ringBase = 0;
     _commandRingLength = 0;
@@ -94,11 +91,13 @@ void uda_c::Reset(void)
     _purgeInterruptEnable = false;
     _next_step = false;
 
+    _server->Reset();
 
     // Signal the worker to begin the initialization sequence.
     StateTransition(InitializationStep::Uninitialized); 
     
-    _server->Reset(); 
+    _sa = 0;
+    update_SA();
 }
 
 uint32_t uda_c::GetDriveCount(void)
@@ -126,7 +125,7 @@ void uda_c::StateTransition(
 
 void uda_c::worker(void)
 {
-    worker_init_realtime_priority(rt_device);
+    worker_init_realtime_priority(rt_max);    
 
     timeout_c timeout;
 
@@ -862,6 +861,7 @@ uda_c::DMAWrite(
     uint8_t* buffer)
 {
     assert ((lengthInBytes % 2) == 0);
+    assert (address < 0x40000);
 
     return unibusadapter->request_DMA(
             UNIBUS_CONTROL_DATO,
@@ -883,6 +883,7 @@ uda_c::DMARead(
 {
     assert (bufferSize >= lengthInBytes);
     assert((lengthInBytes % 2) == 0);
+    assert (address < 0x40000);
 
     uint16_t* buffer = new uint16_t[bufferSize >> 1];