From ad70160847c35231bbbdd345052980c037786815 Mon Sep 17 00:00:00 2001
From: Sebastian Sumpf <sebastian.sumpf@genode-labs.com>
Date: Wed, 26 Sep 2012 14:01:39 +0200
Subject: [PATCH] LWIP: Fix dead lock in semaphore back-end

Make sure unlock is called when 'global_mutex' reaches zero count. Add verbose
variable in order to disable some output. Disable irritating 'Overflow' messages
in 'sys_mbox_post' and 'sys_mbox_try_post' per default. This may happen and is
not an error, since the ring buffer is full and will be emptied eventually.
Remove priority from genode_org run script.

Should fix #347
---
 libports/src/lib/lwip/include/verbose.h    | 22 ++++++++++++++++++++++
 libports/src/lib/lwip/platform/nic.cc      |  4 +++-
 libports/src/lib/lwip/platform/sys_arch.cc | 12 ++++++++----
 ports/run/genode_org.run                   |  2 +-
 4 files changed, 34 insertions(+), 6 deletions(-)
 create mode 100644 libports/src/lib/lwip/include/verbose.h

diff --git a/libports/src/lib/lwip/include/verbose.h b/libports/src/lib/lwip/include/verbose.h
new file mode 100644
index 000000000..a39887635
--- /dev/null
+++ b/libports/src/lib/lwip/include/verbose.h
@@ -0,0 +1,22 @@
+/*
+ * \brief  Enable debugging output
+ * \author Sebastian Sumpf
+ * \date   2012-09-26
+ */
+
+/*
+ * Copyright (C) 2009-2012 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _LWIP__VERBOSE_H_
+#define _LWIP__VERBOSE_H_
+
+/**
+ * Set to one for more output
+ */
+static int verbose = 0;
+
+#endif //_LWIP__VERBOSE_H_
diff --git a/libports/src/lib/lwip/platform/nic.cc b/libports/src/lib/lwip/platform/nic.cc
index bdbd03d6b..f626422ad 100644
--- a/libports/src/lib/lwip/platform/nic.cc
+++ b/libports/src/lib/lwip/platform/nic.cc
@@ -23,6 +23,7 @@ extern "C" {
 #include <netif/etharp.h>
 #include <netif/ppp_oe.h>
 #include <nic.h>
+#include <verbose.h>
 }
 
 /* Genode includes */
@@ -217,7 +218,8 @@ extern "C" {
 		if (p == NULL) return;
 
 		if (netif->input(p, netif) != ERR_OK) {
-			PERR("genode_netif_input: input error");
+			if (verbose)
+				PERR("genode_netif_input: input error");
 			pbuf_free(p);
 			p = 0;
 		}
diff --git a/libports/src/lib/lwip/platform/sys_arch.cc b/libports/src/lib/lwip/platform/sys_arch.cc
index 71dc4b3f5..4b7b47dda 100644
--- a/libports/src/lib/lwip/platform/sys_arch.cc
+++ b/libports/src/lib/lwip/platform/sys_arch.cc
@@ -23,6 +23,7 @@
 #include <timer.h>
 #include <ring_buffer.h>
 #include <thread.h>
+#include <verbose.h>
 
 
 namespace Lwip {
@@ -352,12 +353,13 @@ extern "C" {
 	{
 		if(global_mutex()->thread != Genode::Thread_base::myself())
 			return;
-		if(global_mutex()->counter > 0)
+		if(global_mutex()->counter > 1)
 			global_mutex()->counter--;
 		else {
+			global_mutex()->counter = 0;
 			global_mutex()->thread = 0;
 			global_mutex()->lock.unlock();
-			}
+		}
 	}
 
 
@@ -456,7 +458,8 @@ extern "C" {
 				_mbox->add(msg);
 				return;
 			} catch (Mailbox::Overflow) {
-				PWRN("Overflow exception!");
+				if (verbose)
+					PWRN("Overflow exception!");
 			} catch (...) {
 				PERR("Unknown Exception occured!");
 			}
@@ -481,7 +484,8 @@ extern "C" {
 			_mbox->add(msg);
 			return ERR_OK;
 		} catch (Mailbox::Overflow) {
-			PWRN("Overflow exception!");
+			if (verbose)
+				PWRN("Overflow exception!");
 		} catch (...) {
 			PERR("Unknown Exception occured!");
 		}
diff --git a/ports/run/genode_org.run b/ports/run/genode_org.run
index ab2c8e6c6..81bc5c8d7 100644
--- a/ports/run/genode_org.run
+++ b/ports/run/genode_org.run
@@ -54,7 +54,7 @@ append_if [have_spec pci] config {
 	</start>}
 
 append_if [have_spec omap4] config {
-	<start name="usb_drv" priority="-1">
+	<start name="usb_drv">
 		<resource name="RAM" quantum="12M"/>
 		<provides>
 			<service name="Input"/>