Index: uspace/app/tester/chardev/chardev1.c
===================================================================
--- uspace/app/tester/chardev/chardev1.c	(revision 57914494f0017d0618e3eaa16f2ae9c2fd1baefd)
+++ uspace/app/tester/chardev/chardev1.c	(revision 57914494f0017d0618e3eaa16f2ae9c2fd1baefd)
@@ -0,0 +1,210 @@
+/*
+ * Copyright (c) 2017 Jiri Svoboda
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <ipc/services.h>
+#include <io/chardev.h>
+#include <loc.h>
+#include "../tester.h"
+
+#define SMALL_BUFFER_SIZE 64
+#define LARGE_BUFFER_SIZE (DATA_XFER_LIMIT * 4)
+
+static char small_buffer[SMALL_BUFFER_SIZE];
+static char large_buffer[LARGE_BUFFER_SIZE];
+
+/** Test device that always performs small transfers. */
+static const char *test_chardev1_smallx(void)
+{
+	chardev_t *chardev;
+	service_id_t sid;
+	async_sess_t *sess;
+	size_t nbytes;
+	int rc;
+
+	TPRINTF("Test small transfer character device operations\n");
+
+	rc = loc_service_get_id(SERVICE_NAME_CHARDEV_TEST_SMALLX, &sid, 0);
+	if (rc != EOK) {
+		return "Failed resolving test device "
+		    SERVICE_NAME_CHARDEV_TEST_SMALLX;
+	}
+
+	sess = loc_service_connect(sid, INTERFACE_DDF, 0);
+	if (sess == NULL)
+		return "Failed connecting test device";
+
+	rc = chardev_open(sess, &chardev);
+	if (rc != EOK) {
+		async_hangup(sess);
+		return "Failed opening test device";
+	}
+
+	rc = chardev_write(chardev, small_buffer, SMALL_BUFFER_SIZE, &nbytes);
+	if (rc != EOK) {
+		chardev_close(chardev);
+		async_hangup(sess);
+		return "Failed sending data";
+	}
+
+	TPRINTF("Sent %zu bytes\n", nbytes);
+
+	rc = chardev_read(chardev, small_buffer, SMALL_BUFFER_SIZE, &nbytes);
+	if (rc != EOK) {
+		chardev_close(chardev);
+		async_hangup(sess);
+		return "Failed receiving data";
+	}
+
+	TPRINTF("Received %zu bytes\n", nbytes);
+
+	chardev_close(chardev);
+	async_hangup(sess);
+
+	TPRINTF("Done\n");
+	return NULL;
+}
+
+/** Test device that always performs large transfers. */
+static const char *test_chardev1_largex(void)
+{
+	chardev_t *chardev;
+	service_id_t sid;
+	async_sess_t *sess;
+	size_t nbytes;
+	int rc;
+
+	TPRINTF("Test large transfer character device operations\n");
+
+	rc = loc_service_get_id(SERVICE_NAME_CHARDEV_TEST_LARGEX, &sid, 0);
+	if (rc != EOK) {
+		return "Failed resolving test device "
+		    SERVICE_NAME_CHARDEV_TEST_LARGEX;
+	}
+
+	sess = loc_service_connect(sid, INTERFACE_DDF, 0);
+	if (sess == NULL)
+		return "Failed connecting test device";
+
+	rc = chardev_open(sess, &chardev);
+	if (rc != EOK) {
+		async_hangup(sess);
+		return "Failed opening test device";
+	}
+
+	rc = chardev_write(chardev, large_buffer, LARGE_BUFFER_SIZE, &nbytes);
+	if (rc != EOK) {
+		chardev_close(chardev);
+		async_hangup(sess);
+		return "Failed sending data";
+	}
+
+	TPRINTF("Sent %zu bytes\n", nbytes);
+
+	rc = chardev_read(chardev, large_buffer, LARGE_BUFFER_SIZE, &nbytes);
+	if (rc != EOK) {
+		chardev_close(chardev);
+		async_hangup(sess);
+		return "Failed receiving data";
+	}
+
+	TPRINTF("Received %zu bytes\n", nbytes);
+
+	chardev_close(chardev);
+	async_hangup(sess);
+
+	TPRINTF("Done\n");
+	return NULL;
+}
+
+/** Test device where all transfers return partial success. */
+static const char *test_chardev1_partialx(void)
+{
+	chardev_t *chardev;
+	service_id_t sid;
+	async_sess_t *sess;
+	size_t nbytes;
+	int rc;
+
+	TPRINTF("Test partially-successful character device operations\n");
+
+	rc = loc_service_get_id(SERVICE_NAME_CHARDEV_TEST_PARTIALX, &sid, 0);
+	if (rc != EOK) {
+		return "Failed resolving test device "
+		    SERVICE_NAME_CHARDEV_TEST_SMALLX;
+	}
+
+	sess = loc_service_connect(sid, INTERFACE_DDF, 0);
+	if (sess == NULL)
+		return "Failed connecting test device";
+
+	rc = chardev_open(sess, &chardev);
+	if (rc != EOK) {
+		async_hangup(sess);
+		return "Failed opening test device";
+	}
+
+	rc = chardev_write(chardev, small_buffer, SMALL_BUFFER_SIZE, &nbytes);
+	if (rc != EIO || nbytes != 1) {
+		chardev_close(chardev);
+		async_hangup(sess);
+		return "Failed sending data";
+	}
+
+	TPRINTF("Sent %zu bytes and got rc = %d (expected)\n", nbytes, rc);
+
+	rc = chardev_read(chardev, small_buffer, SMALL_BUFFER_SIZE, &nbytes);
+	if (rc != EIO || nbytes != 1) {
+		chardev_close(chardev);
+		async_hangup(sess);
+		return "Failed receiving data";
+	}
+
+	TPRINTF("Received %zu bytes and got rc = %d (expected)\n", nbytes, rc);
+
+	chardev_close(chardev);
+	async_hangup(sess);
+
+	TPRINTF("Done\n");
+	return NULL;
+}
+
+const char *test_chardev1(void)
+{
+	const char *s;
+
+	s = test_chardev1_smallx();
+	if (s != NULL)
+		return s;
+
+	s = test_chardev1_largex();
+	if (s != NULL)
+		return s;
+
+	return test_chardev1_partialx();;
+}
