Changeset 91ecaa10 in mainline

Timestamp:

2012-08-12T23:14:48Z (12 years ago)

Author:

Martin Sucha <sucha14@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

58a369e

Parents:

6e09bee

Message:

Make ns8250 read blocking.

File:

• uspace/drv/char/ns8250/ns8250.c (modified) (5 diffs)

uspace/drv/char/ns8250/ns8250.c

@@ -179 +179 @@
         /** 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 +240 @@
 {
         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);
@@ -739 +745 @@
                         
                         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 "
@@ -746 +753 @@
                                             "to the buffer of %s.",
                                             val, ns->dev->name);
+                                        if (buf_was_empty)
+                                                fibril_condvar_broadcast(&ns->input_buffer_available);
                                 }
                         }
@@ -811 +820 @@
         
         fibril_mutex_initialize(&ns->mutex);
+        fibril_condvar_initialize(&ns->input_buffer_available);
         ns->dev = dev;