--quiet has been added to g-ir-scanner in the 0.9.1 cycle. We really
want to be able to compile clutter with 0.6.14 to be able to reuse
gir files that are distributed in current distributions.
Use the INTROSPECTION_SCANNER_ARGS (previously unused) variable to
convey --quiet when necessary.
Fixes: http://bugzilla.clutter-project.org/show_bug.cgi?id=2265
DRM is available on more platforms than Linux (e.g. kFreeBSD), but
Clutter currently FTBFS there because of not being an alternative to
the __linux__ code (where it should be HAVE_DRM).
Instead of copying the DRM data structures, we should use libdrm when
falling back to directly requesting to wait for the vblank.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2225
Based on a patch by: Emilio Pozuelo Monfort <pochu27@gmail.com>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
In 7fae8ac051 the two cogl-defines.h files from GLES and GL were
unified. However this missed out the COGL_HAS_GLES[12] defines from
GLES. The configure.ac still made an AC_SUBST for the right version
but the replacement was never put in any headers. This fixes it so
that instead of directly calling AC_SUBST the value is now put into a
variable which later gets added to COGL_DEFINES so that it will end up
in cogl-defines.h
There was an initializer for the COGL_DEFINES variable which sets it
to the empty value before it is filled in. The name of the variable
wasn't spelt right so it wouldn't work properly. This doesn't really
matter because it would default to empty anyway.
The cookbook should also include fully functional code examples. We can
even XInclude them into the docbook XML itself.
The examples should be built with the coobook, so that we can always
make sure they are up to date.
The P_() macro adds a context for the property nick and blurb. In order
to make xgettext recognize it, we need to drop glib-gettexize inside the
autogen.sh script and ship a modified Makefile.in.in with Clutter.
The AS_ALL_LINGUAS m4 macro allows configure-time generation of the
ALL_LINGUAS variable from the translations inside po/ instead of using
the LINGUAS file.
* wip/xkb-support:
x11: Use XKB to translate keycodes into key symbols
x11: Use XKB to track the Locks state
x11: Use XKB detectable auto-repeat
x11: Add a Keymap ancillary object
x11: Store the group inside the event platform data
events: Add platform-data to allocated Events
build: Check for the XKB extension
Under big GL, glext.h is included automatically by gl.h. However under
GLES this doesn't appear to happen so it has to be included explicitly
to get the defines for extensions. This patch changes the
clutter_gl_header to be called cogl_gl_headers and it can now take a
space seperated list of multiple headers. This is then later converted
to a list of #include lines which ends up cogl-defines.h. The gles2
and gles1 backends now add their respective ext header to this list.
* cally-merge:
cally: Add introspection generation
cally: Improving cally doc
cally: Cleaning CallyText
cally: Refactoring "window:create" and "window:destroy" emission code
cally: Use proper backend information on CallyActor
cally: Check HAVE_CONFIG_H on cally-util.c
docs: Fix Cally documentation
cally: Clean up the headers
Add binaries of the Cally examples to the ignore file
docs: Add Cally API reference
Avoid to load cally module on a11y examples
Add accessibility tests
Initialize accessibility support on clutter_init
Rename some methods and includes to avoid -Wshadow warnings
Cally initialization code
Add Cally
We now always aim to use pkg-config based configuration when possible,
but when not configure.ac now knows the difference between GLES_CM
libraries that contain EGL symbols (I.e. a separate EGL library doesn't
need to be found) and GLESv1_CM libraries that don't contain EGL
symbols.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2160
I was fed up to cd into the tests/conform or tests/interactive directories
to launch a specific test. Now, with the power the abs_ variants of
builddir and srcdir we can run specific test from any directory.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2159
The Clutter Accessibility Library is an implementation of the ATK,
the Accessibility Toolkit, which exposes Clutter actors to accessibility
tools. This allows not only writing accessible user interfaces, but also
allows testing and verification frameworks based on A11Y technologies to
inspect and test a Clutter scene graph.
http://bugzilla.clutter-project.org/show_bug.cgi?id=2097
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
This copies the files for the GLU tesselator from Mesa. The Mesa code
is based on the original SGI code and is released under a BSD license.
The memalloc.h header has been replaced with one that forces the code
to use g_malloc and friends. The rest of the files are not altered
from the original so it should be possible to later upgrade the files
by simply overwriting them.
There is a tesselator.h header which is expected to be included by
rest of Cogl to use the tesselator. This contains a trimmed down
version of glu.h that only includes parts that pertain to the
tesselator. There is also a stub glu.h in the GL directory which is
just provided so that the tesselator code can include <GL/gl.h>
without depending on the system header. It just redirects to
tesselator.h
The -Bsymbolic-functions linker flag allows to avoid intra-library
PLT jumps on ELF platforms. It is similar to the aliasing hack in
GLib and GTK+, but definitely less messy.
The configure script should look for the flags, in order to support
platforms/linkers that do not have it.
This will be defined in cogl-defines.h whenever Cogl is built using a
winsys that supports X11. This implies CoglTexturePixmapX11 will be
available.
To make this work the two separate cogl-defines.h.in files have been
merged into one. The configure script now makes a @COGL_DEFINES@
substitution variable which contains the #define lines to put in
rather than directly having them in the seperate files.
When configuring the glx flavour we were always explicitly adding -lGL
to the linker flags even when a pkg-config file was found which should
take care of that option for us.
When building for gles1/2 we now always try and look for a libglesv1_cm
or libglesv2 .pc file with details about where to find the library and
headers.
This adds an automake USE_TSLIB condition to decide when we should
compile clutter-event-tslib.c. This is in preparation for consolidating
the eglx and eglnative backends.
With this patch if you ./configure clutter using
--with-flavour=opengl-egl-xlib then it will use EGL + OpenGL instead of
the default GLX and OpenGL.
These days upstream driver work is more focused on improving EGL than it
is GLX so likewise we want to make sure Clutter has good support for
EGL.
This adds a separate variable name "CLUTTER_SONAME_INFIX" to define the
infix for the clutter library that gets linked. Currently the WINSYS
corresponds to the directory we enter when building to compile the
window system and input support, but it is desirable to be able to
define multiple flavours that use the same WINSYS but should result in
different library names.
For example we are planning to combine the eglx and eglnative window
systems into one "egl" winsys but we will need to preserve the current
library names for the eglx and eglnative flavours.
When we check the flavour we now just set boolean variables for the
following things:
SUPPORT_X11=1
SUPPORT_XLIB=1
SUPPORT_GLX=1
SUPPORT_EGL=1
SUPPORT_EGL_POWERVR_X11=1
SUPPORT_EGL_POWERVR_NULL=1
This lets us avoid some duplication and also some error prone tests for
lists of flavours used, for example, to determine when we need to check
for x libraries.
It's desirable to have a separation between the "flavour" and the
"winsys". The flavour is a concept internal to the configure script and
is a convenient name to represent the users choice of window system,
opengl driver and input backend. The CLUTTER_WINSYS currently defines
the subdirectory under clutter/ that should be compiled to handle the
window system and input.
With a separation we could add a flavour with no correspondence to which
clutter/subdirectory needs to be built.
After checking the flavour option the user gives we were checking for
the fruity flavour to override the glesversion. Now that the glsl
checking has been moved this can instead just wait until the AS_CASE
that handles all the flavour configuration.
The flavour AS_CASE should define whether a flavour uses the gl or gles
COGL_DRIVER and so we shouldn't need to have an expanding list of
tests to gate when we check for a gles driver because if we move the
checks for gles after the flavour checks we can just look at
$COGL_DRIVER.
This removes EGL_{LIBS,CFLAGS}, GLX_{LIBS,CFLAGS}, OSX_{LIBS,CFLAGS},
WIN32_{LIBS,CFLAGS}, and GLES_{LIBS,CFLAGS} and instead we just append
to FLAVOUR_{LIBS,CFLAGS}.
This makes more of the file relocatable because there were previously
dependencies on the order that some variables were setup in.
* wip/constraints: (24 commits)
Add the Cogl API reference to the fixxref extra directories
Document the internal MetaGroup class
Remove the construct-only flag from ActorMeta:name
doc: Remove gtk-doc annotations from the json-glib copy
doc: Fix parameter documentation
Add named modifiers for Action and Constraint
Remove a redundant animation
Set the stage resizable in test-constraints
Use a 9 grid for the constraints test
Miscellaneous documentation fixes
docs: Document animating action and constraint properties
docs: Document BindConstraint and AlignConstraint
constraint: Rename BindConstraint:bind-axis
constraints: Add AlignConstraint
tests: Add a constraints interactive test
constraint: Add BindConstraint
actor: Implement Animatable
animation: Use the new Animatable API for custom properties
animatable: Add custom properties to Animatable
constraint: Add ClutterConstraint base class
...
Conflicts:
configure.ac
This exposes the ./configured window system/backend options to Cogl via
a set of new COGL_HAS_XYZ_SUPPORT defines:
COGL_HAS_{X11,XLIB,GLX,EGL,EGL_PLATFORM_XYZ,OSX,WIN32,WGL}_SUPPORT
The AM_PATH_GLIB_2_0 doesn't automatically cause the configure script
to fail if the test fails. This wouldn't usually cause any problems
because we later check for the right glib version using
PKG_CHECK_MODULES directly. However AM_PATH_GLIB_2_0 is more thorough
when checking because it also tries to run a program against the
library to read the version. If the macro fails but the pkg-config
check passes then nothing will define GLIB_GENMARSHAL and the build
step will fail in a confusing way.
This adds a check for the result and gives an AC_MSG_ERROR if it
fails. The glib dependencies have been moved out of CLUTTER_DEPS to
AM_PATH_GLIB_2_0.
http://bugzilla.openedhand.com/show_bug.cgi?id=2127
The system JSON-GLib installation should be the preferred way of parsing
JSON in Clutter. The internal copy is limited by re-synchronization from
upstream, and by the fact that upstream contains a fork of GScanner that
allows parsing escaped UTF-8. We should warn users compiling Clutter
with the internal copy, just like we warn about the internal image
backend.
The X11TexturePixmap actor uses XComposite API directly, without guards.
It has been doing so for a while, against the fact that we do check for
the XComposite extension - but we don't depend on it. As soon as you try
building Clutter on X11 without the XComposite extension available all
hell breaks loose.
The obvious fix is to make Clutter depend on XComposite - basically
ratifying what's the current state of things.
Update the configure.ac to use the LT_INIT() instead of the deprecated
AC_PROG_LIBTOOL. This also allows us to depend on a specific libtool
version, namely one that doesn't thoroughly suck.
There is no need for us to check for low-level functions and header
files, especially since we haven't been checking the results until
now. This makes cross-compiling slightly more bearable.
Require automake >= 1.10, and add the following options:
» dist-bzip2: create a bz2 tarball in the dist process
» check-news: check that we changed the NEWS file prior to dist,
to avoid another release without NEWS updates, like 1.1.10
We basically want all Clutter applications out in the wild to at least
have the basic set of COGL_DEBUG/--cogl-debug options available for
investigating issues.
The SDL API is far too limited for the windowing system needs of
Clutter; the status of the SDL backend was always experimental, and
since the Windows platform is supported by a native backend there is
no point in having the SDL backend around any more.
When using pkg-config to check for the x11 package compiler flags and
libraries we actually need to retrieve those values from the pc file.
This should also fix the issue with non-canonical installations of the
X11 headers and shared objects.
http://bugzilla.openedhand.com/show_bug.cgi?id=1966
The win32 backend now handles the WM_SETCURSOR message and sets a
fully transparent cursor if the cursor-visible property has been
cleared on the stage. The icon is stored in the library via a resource
file. The instance handle for the DLL is needed to load the resource
so there is now a DllMain function to grab the handle.
This adds gives Cogl a dedicated UProf context which will be linked together
with Clutter's context during clutter_init_real().
Initial timers cover _cogl_journal_flush and _cogl_journal_log_quad
You can explicitly ask for a report of Cogl statistics by exporting
COGL_PROFILE_OUTPUT_REPORT=1 but since the context is linked with Clutter's
the statisitcs will also be shown in the automatic Clutter reports.
• Make the manual a DevHelp book
• Make the generation of PDFs of the cookbook and the manual optional
• Consequently, make the hard dependency on jw optional
• Clean up the checks and build for the additional documentation
Instead of creating stand-alone HTML files, use XSLT to transform the
DocBook into a DevHelp file, so that we can read the Cookbook inside
DevHelp -- just like the API reference.
The "Clutter Cookbook" is a document designed to contain solutions
to common problems applications developers might encounter when using
Clutter. It is meant as a companion to the API reference but it
requires knowledge of the Clutter API and framework.
The main COGL header cogl.h is currently created at configure time
because it conditionally includes the driver-dependent defines. This
sometimes leads to a stale cogl.h with old definitions which can
break the build until you clean out the whole tree and start from
scratch.
We can generate a stable cogl-defines.h at build time from the
equivalent driver-dependent header and let cogl.h include that
file instead.
We should generate a ChangeLog for each minor version cycle, starting
from the Git import date (since before that we used ChangeLog-style
commit messages that don't really look good with the Git ones).
For this reason we can take Cairo's Makefile.am.changelog file and,
after tweaking it to fit our use case, let it generate the correct
ChangeLogs on dist.
Some changes to make COGL pass distcheck with Automake 1.11 and
anal-retentiveness turned up to 11.
The "major" change is the flattening of the winsys/ part of COGL,
which is built directly inside libclutter-cogl.la instead of an
intermediate libclutter-cogl-winsys.la object.
Ideally, the whole COGL should be flattened out using a
quasi-non-recursive Automake layout; unfortunately, the driver/
sub-section ships with identical targets and Automake cannot
distinguish GL and GLES objects.
As part of an incremental process to have Cogl be a standalone project we
want to re-consider how we organise the Cogl source code.
Currently this is the structure I'm aiming for:
cogl/
cogl/
<put common source here>
winsys/
cogl-glx.c
cogl-wgl.c
driver/
gl/
gles/
os/ ?
utils/
cogl-fixed
cogl-matrix-stack?
cogl-journal?
cogl-primitives?
pango/
The new winsys component is a starting point for migrating window system
code (i.e. x11,glx,wgl,osx,egl etc) from Clutter to Cogl.
The utils/ and pango/ directories aren't added by this commit, but they are
noted because I plan to add them soon.
Overview of the planned structure:
* The winsys/ API is the API that binds OpenGL to a specific window system,
be that X11 or win32 etc. Example are glx, wgl and egl. Much of the logic
under clutter/{glx,osx,win32 etc} should migrate here.
* Note there is also the idea of a winsys-base that may represent a window
system for which there are multiple winsys APIs. An example of this is
x11, since glx and egl may both be used with x11. (currently only Clutter
has the idea of a winsys-base)
* The driver/ represents a specific varient of OpenGL. Currently we have "gl"
representing OpenGL 1.4-2.1 (mostly fixed function) and "gles" representing
GLES 1.1 (fixed funciton) and 2.0 (fully shader based)
* Everything under cogl/ should fundamentally be supporting access to the
GPU. Essentially Cogl's most basic requirement is to provide a nice GPU
Graphics API and drawing a line between this and the utility functionality
we add to support Clutter should help keep this lean and maintainable.
* Code under utils/ as suggested builds on cogl/ adding more convenient
APIs or mechanism to optimize special cases. Broadly speaking you can
compare cogl/ to OpenGL and utils/ to GLU.
* clutter/pango will be moved to clutter/cogl/pango
How some of the internal configure.ac/pkg-config terminology has changed:
backendextra -> CLUTTER_WINSYS_BASE # e.g. "x11"
backendextralib -> CLUTTER_WINSYS_BASE_LIB # e.g. "x11/libclutter-x11.la"
clutterbackend -> {CLUTTER,COGL}_WINSYS # e.g. "glx"
CLUTTER_FLAVOUR -> {CLUTTER,COGL}_WINSYS
clutterbackendlib -> CLUTTER_WINSYS_LIB
CLUTTER_COGL -> COGL_DRIVER # e.g. "gl"
Note: The CLUTTER_FLAVOUR and CLUTTER_COGL defines are kept for apps
As the first thing to take advantage of the new winsys component in Cogl;
cogl_get_proc_address() has been moved from cogl/{gl,gles}/cogl.c into
cogl/common/cogl.c and this common implementation first trys
_cogl_winsys_get_proc_address() but if that fails then it falls back to
gmodule.
Following bug #1762, the syntax of g-ir-scanner was changed in
gobject-introspection, so Clutter does not build anymore with 0.6.4.
See the bugzilla bug:
http://bugzilla.gnome.org/show_bug.cgi?id=591669
GObject-Introspection now uses a different mechanism to extract the
SONAME when building the gir file and it needs the libtool archive as
option.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
Currently, Clutter depends on the internal copy of JSON-GLib for
the ClutterScript parser. This is done to allow building Clutter
on platforms that do not have the library installed on the system.
Just like we use the internal PNG/JPEG loader as a fallback in
case we don't have GdkPixbuf or CoreGraphics available, we should
use the internal copy of JSON-GLib only in case the system copy
is not present.
The change is simply to move the default for the --with-json
configure switch from "internal" to "check".
In order to allow stricter compliance, a third setting should
be present: "system", which fails if the system copy is not
available.
We should also change the introspection generation to avoid
breaking in case we require the installed Json-1.0.gir instead
of the generated ClutterJson.gir
Instead of using a specific function to check whether the X
server supports the XInput extension we can use the generic
Xlib function XQueryExtension(). This cuts down the extra
checks inside the configure.ac and simplifies the code inside
clutter_x11_register_xinput().
HAVE_COGL_GLES2 is defined in config.h through the configure script and
should not be used in public headers.
The patch makes configure generate the right define that can be used
later in the header.
Instead of blacklisting experimental features at the end we can
explicitly mark backends and image backends near their checks and
provide a summary at the end.
Use the AS_COMPILER_FLAGS to check whether the maintainer compiler flags
we use are supported; this should fail gracefully and only use the ones
that the compiler actually understands.
Fixes bug:
http://bugzilla.openedhand.com/show_bug.cgi?id=1639
It seems GNU Gold (the new linker) either behaves as if with
--no-undefined by default, or has some issue preventing it from not
doing that when instructed to (I'm not sure if this actually
happens). In any case, clutter uses the Xshm extensions, but does not
link to libXext, which makes gold unhappy.
Based on a patch by: Xan Lopez <xan@gnome.org>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
A merge conflict gone bad: the IMAGE_PC_FILES variable was not appended
to the CLUTTER_REQUIRES one, thus leading to Clutter depending on
GdkPixbuf but never actually checking for it.
* 1.0-integration: (138 commits)
[x11] Disable XInput by default
[xinput] Invert the XI extension version check
[cogl-primitives] Fix an unused variable warning when building GLES
[clutter-stage-egl] Pass -1,-1 to clutter_stage_x11_fix_window_size
Update the GLES backend to have the layer filters in the material
[gles/cogl-shader] Add a missing semicolon
[cogl] Move the texture filters to be a property of the material layer
[text] Fix Pango unit to pixels conversion
[actor] Force unrealization on destroy only for non-toplevels
[x11] Rework map/unmap and resizing
[xinput] Check for the XInput entry points
[units] Validate units against the ParamSpec
[actor] Add the ::allocation-changed signal
[actor] Use flags to control allocations
[units] Rework Units into logical distance value
Remove a stray g_value_get_int()
Remove usage of Units and macros
[cogl-material] Allow setting a layer with an invalid texture handle
[timeline] Remove the concept of frames from timelines
[gles/cogl-shader] Fix parameter spec for cogl_shader_get_info_log
...
Conflicts:
configure.ac
The XInput support in Clutter is still using XI 1.x. This will never
work correctly, and we are all waiting for XInput 2 anyway. The changes
internally should be minimal, so we can leave everything in place, but
it's better to disable XInput support by default -- at least for the
time being.
Apparently, the XInput extension is using the same pkg-config
file ('xi') for both the 1.x and the 2.x API, so we need to
check for both the 1.x XGetExtensionVersion and the 2.x
XQueryInputVersion.
Clutter copies the gtk-doc from the usual gtk+ template, and
has a version.xml.in containing only:
@VERSION@
Without a newline at the end. Unfortunately, it appears that
autoconf has started adding a newline to the generated version.xml
which then is used as the payload for the "version" XML entity.
Instead of using a secondary file we can make configure generate
the whole clutter-docs.xml and cogl-docs.xml files from a template;
this way we also get the ability to substitute more autoconf variables
into the documentation -- if needs be.
Using --enable-debug, which controls Clutter's debug level, also
defines COGL_ENABLE_DEBUG. This should be left to --enable-cogl-debug
instead, since it's the configure switch that controls COGL debug
level.
Let's try to bring configure.ac into this century, shall we?
* Use the proper shell macros AS_IF and AS_CASE instead of if...fi
and case...esac
* Check for X11 and relative extensions only when building for GLX
and EGLX backends
* Add documentation on the behaviour of binary_age and interface_age
* Coalesce all the common checks to avoid redundancy
* Escape everything that requires escaping
Currently, COGL depends on defining debug symbols by manually
modifying the source code. When it's done, it will forcefully
print stuff to the console.
Since COGL has also a pretty, runtime selectable debugging API
we might as well switch everything to it.
In order for this to happen, configure needs a new:
--enable-cogl-debug
command line switch; this will enable COGL debugging, the
CoglHandle debugging and will also turn on the error checking
for each GL operation.
The default setting for the COGL debug defines is off, since
it slows down the GL operations; enabling it for a particular
debug build is trivial, though.
This update fixes a few issues:
- the use of shave with mingw32 bash on windows,
- fix the unmangling of libtool names
- fix build on solaris
- add an --enable/disable-shave configure option (while still
defaulting to enabled)
COGL should ship its own pkg-config file, obviously still pointing
to Clutter's compiler flags and linking options, for COGL-specific
variables that might be queried at configure time.
For instance, it's easier (and less verbose) to do:
PKG_CHECK_EXISTS([cogl-gl-1.0],
[has_gl_backend=yes],
[has_gl_backend=no])
Than doing:
AC_MSG_CHECKING([for GL support in COGL])
cogl_backend=`$PKG_CONFIG --variable=cogl clutter-0.9`
if test x$cogl_backend = xgl; then
has_gl_backend=yes
AC_MSG_RESULT([found])
else
has_gl_backend=no
AC_MSG_RESULT([not found])
fi
If X11 comes with pkg-config files (like it should) we should not add
those dependencies to the generic BACKEND_PC_FILES variable: that
variable is meant only for backend-specific dependencies handled by
pkg-config -- and Clutter supports non-X11 backends as well.
The X11_PC_FILES variable will only contain X11-related dependencies,
and will be set as part of BACKEND_PC_FILES only inside the GLX and
EGLX backends sections.
Clutter is able to show debug messages written using the CLUTTER_NOTE()
macro at runtime, either by using an environment variable:
CLUTTER_DEBUG=...
or by using a command line switch:
--clutter-debug=...
--clutter-no-debug=...
Both are parsed during the initialization process by using the
GOption API.
COGL would benefit from having the same support.
In order to do this, we need a cogl_get_option_group() function in
COGL that sets up a GOptionGroup for COGL and adds a pre-parse hook
that will check the COGL_DEBUG environment variable. The OptionGroup
will also install two command line switches:
--cogl-debug
--cogl-no-debug
With the same semantics of the Clutter ones.
During Clutter initialization, the COGL option group will be attached
to the GOptionContext used to parse the command line options passed
to a Clutter application.
Every debug message written using:
COGL_NOTE (SECTION, "message format", arguments);
Will then be printed only if SECTION was enabled at runtime.
This whole machinery, like the equivalent one in Clutter, depends on
a compile time switch, COGL_ENABLE_DEBUG, which is enabled at the same
time as CLUTTER_ENABLE_DEBUG. Having two different symbols allows
greater granularity.
configure.ac: Check for gobject-introspection
build/introspection.m4: Include the file that defines the
GOBJECT_CHECK_INTROSPECTION m4 macro in case we want to disable
the introspection data generation.
clutter/json/Makefile.am: Build the .gir for "ClutterJson"
(json-glib as part of the Clutter library)
clutter/Makefile.am: Build the .gir for clutter, compile the
Clutter and ClutterJson girs into typelibs, and install them.
Also move GCC_FLAGS from $(INCLUDES) to $(AM_CFLAGS) since it includes
non-preprocessor flag like -Wall.
See also:
http://bugzilla.openedhand.com/show_bug.cgi?id=1450
Based on a patch by: Owen W. Taylor <otaylor@fishsoup.net>
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>