Changes in uspace/drv/char/ns8250/ns8250.c [c7235d40:c92e30f] in mainline

File:

• uspace/drv/char/ns8250/ns8250.c (modified) (11 diffs)

uspace/drv/char/ns8250/ns8250.c

@@ -82 +82 @@
 /** Interrupt ID Register definition. */
 #define NS8250_IID_ACTIVE       (1 << 0)
+#define NS8250_IID_CAUSE_MASK 0x0e
+#define NS8250_IID_CAUSE_RXSTATUS 0x06
 
 /** FIFO Control Register definition. */
@@ -179 +181 @@
         /** The fibril mutex for synchronizing the access to the device. */
         fibril_mutex_t mutex;
+        /** Indicates that some data has become available */
+        fibril_condvar_t input_buffer_available;
         /** True if device is removed. */
         bool removed;
@@ -238 +242 @@
 {
         ns8250_t *ns = NS8250(fun);
-        int ret = EOK;
+        int ret = 0;
+        
+        if (count == 0) return 0;
         
         fibril_mutex_lock(&ns->mutex);
+        while (buf_is_empty(&ns->input_buffer))
+                fibril_condvar_wait(&ns->input_buffer_available, &ns->mutex);
         while (!buf_is_empty(&ns->input_buffer) && (size_t)ret < count) {
                 buf[ret] = (char)buf_pop_front(&ns->input_buffer);
@@ -460 +468 @@
 {
         /* Interrupt when data received. */
-        pio_write_8(&regs->ier, NS8250_IER_RXREADY);
+        pio_write_8(&regs->ier, NS8250_IER_RXREADY | NS8250_IER_RXSTATUS);
         pio_write_8(&regs->mcr, NS8250_MCR_DTR | NS8250_MCR_RTS 
             | NS8250_MCR_OUT2);
@@ -499 +507 @@
         async_exchange_end(exch);
 
+        /* Read LSR to clear possible previous LSR interrupt */
+        pio_read_8(&ns->regs->lsr);
+
         /* Enable interrupt on the serial port. */
         ns8250_port_interrupts_enable(ns->regs);
@@ -695 +706 @@
         /* 8 bits, no parity, two stop bits. */
         ns8250_port_set_com_props(ns->regs, SERIAL_NO_PARITY, 8, 2);
-        /* Enable FIFO, clear them, with 14-byte threshold. */
+        /*
+         * Enable FIFO, clear them, with 4-byte threshold for greater
+         * reliability.
+         */
         pio_write_8(&ns->regs->iid, NS8250_FCR_FIFOENABLE
-            | NS8250_FCR_RXFIFORESET | NS8250_FCR_TXFIFORESET 
-            | NS8250_FCR_RXTRIGGERLOW | NS8250_FCR_RXTRIGGERHI);
+            | NS8250_FCR_RXFIFORESET | NS8250_FCR_TXFIFORESET
+            | NS8250_FCR_RXTRIGGERLOW);
         /*
          * RTS/DSR set (Request to Send and Data Terminal Ready lines enabled),
@@ -731 +745 @@
         bool cont = true;
         
+        fibril_mutex_lock(&ns->mutex);
         while (cont) {
-                fibril_mutex_lock(&ns->mutex);
-                
                 cont = ns8250_received(regs);
                 if (cont) {
@@ -739 +752 @@
                         
                         if (ns->client_connected) {
+                                bool buf_was_empty = buf_is_empty(&ns->input_buffer);
                                 if (!buf_push_back(&ns->input_buffer, val)) {
                                         ddf_msg(LVL_WARN, "Buffer overflow on "
                                             "%s.", ns->dev->name);
+                                        break;
                                 } else {
                                         ddf_msg(LVL_DEBUG2, "Character %c saved "
                                             "to the buffer of %s.",
                                             val, ns->dev->name);
+                                        if (buf_was_empty)
+                                                fibril_condvar_broadcast(&ns->input_buffer_available);
                                 }
                         }
                 }
-                
-                fibril_mutex_unlock(&ns->mutex);
-                fibril_yield();
-        }
+        }
+        fibril_mutex_unlock(&ns->mutex);
+        fibril_yield();
 }
 
 /** The interrupt handler.
  *
- * The serial port is initialized to interrupt when some data come, so the
- * interrupt is handled by reading the incomming data.
+ * The serial port is initialized to interrupt when some data come or line
+ * status register changes, so the interrupt is handled by reading the incoming
+ * data and reading the line status register.
  *
  * @param dev           The serial port device.
@@ -765 +782 @@
     ipc_call_t *icall)
 {
-        ns8250_read_from_device(NS8250_FROM_DEV(dev));
+        ns8250_t *ns = NS8250_FROM_DEV(dev);
+
+        uint8_t iir = pio_read_8(&ns->regs->iid);
+        if ((iir & NS8250_IID_CAUSE_MASK) == NS8250_IID_CAUSE_RXSTATUS) {
+                uint8_t lsr = pio_read_8(&ns->regs->lsr);
+                if (lsr & NS8250_LSR_OE) {
+                        ddf_msg(LVL_WARN, "Overrun error on %s", ns->dev->name);
+                }
+        }
+        
+        ns8250_read_from_device(ns);
 }
 
@@ -811 +838 @@
         
         fibril_mutex_initialize(&ns->mutex);
+        fibril_condvar_initialize(&ns->input_buffer_available);
         ns->dev = dev;
         
@@ -1053 +1081 @@
 static void ns8250_init(void)
 {
-        ddf_log_init(NAME, LVL_ERROR);
+        ddf_log_init(NAME, LVL_WARN);
         
         ns8250_dev_ops.open = &ns8250_open;