Another attempt to get CMSIS semaphores correct.

src/gos/gos_cmsis.c

@@ -43,9 +43,9 @@ void gfxSemInit(gfxSem* psem, semcount_t val, semcount_t limit)
 	osSemaphoreDef_t def;
 	def.semaphore = psem->semaphore;
 	
-	psem->id = osSemaphoreCreate(&def, limit);
+	if (val > limit) val = limit;
-	while(val--)
+	psem->available = limit - val;
-		osSemaphoreRelease(psem->id);
+	psem->id = osSemaphoreCreate(&def, val);
 }
 
 void gfxSemDestroy(gfxSem* psem)
@@ -55,22 +55,29 @@ void gfxSemDestroy(gfxSem* psem)
 
 bool_t gfxSemWait(gfxSem* psem, delaytime_t ms)
 {
-	return osSemaphoreWait(psem->id, ms) > 0;
+	if (osSemaphoreWait(psem->id, ms) == osOK) {
+		psem->available++;
+		return TRUE;
+	}
+	return FALSE;
 }
 
 bool_t gfxSemWaitI(gfxSem* psem)
 {
-	return osSemaphoreWait(psem->id, 0) > 0;
+	return gfxSemWait(psem, 0);
 }
 
 void gfxSemSignal(gfxSem* psem)
 {
-	osSemaphoreRelease(psem->id);
+	gfxSemSignalI(psem);
 }
 
 void gfxSemSignalI(gfxSem* psem)
 {
+	if (psem->available) {
+		psem->available--;
 		osSemaphoreRelease(psem->id);
+	}
 }
 
 gfxThreadHandle gfxThreadCreate(void* stackarea, size_t stacksz, threadpriority_t prio, DECLARE_THREAD_FUNCTION((*fn),p), void* param)

src/gos/gos_cmsis.h

@@ -44,6 +44,7 @@ typedef osPriority			threadpriority_t;
 typedef struct gfxSem {
 	uint32_t		semaphore[2];
 	osSemaphoreId	id;
+	semcount_t		available;
 } gfxSem;
 
 typedef struct gfxMutex {