Changeset c657bd7 in mainline for uspace/drv/char/pl050/pl050.c

Timestamp:

2017-11-20T10:06:59Z (6 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

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

Children:

19ea61d

Parents:

5d50c419

git-author:

Jiri Svoboda <jiri@…> (2017-11-19 22:05:26)

git-committer:

Jiri Svoboda <jiri@…> (2017-11-20 10:06:59)

Message:

Less is sometimes more. Need chardev_read to be able to return less bytes than requested if less is available. Otherwise cannot read variable-sized packets except yte-by-byte.

File:

• uspace/drv/char/pl050/pl050.c (modified) (2 diffs)

uspace/drv/char/pl050/pl050.c

@@ -246 +246 @@
         left = size;
         while (left > 0) {
-                while (pl050->buf_rp == pl050->buf_wp)
+                while (left == size && pl050->buf_rp == pl050->buf_wp)
                         fibril_condvar_wait(&pl050->buf_cv, &pl050->buf_lock);
+                if (pl050->buf_rp == pl050->buf_wp)
+                        break;
                 *bp++ = pl050->buffer[pl050->buf_rp];
                 --left;
@@ -255 +257 @@
         fibril_mutex_unlock(&pl050->buf_lock);
 
-        return size;
+        return size - left;
 }