Using the extension saves a bit of code.
Miscellanea:
o Neaten and simplify dump_dp_payload_table
o Removed trailing blank space from output
$ size drivers/gpu/drm/drm_dp_mst_topology.o.* drivers/gpu/drm/tinydrm/*.o*
text data bss dec hex filename
25848 0 16 25864 6508 drivers/gpu/drm/drm_dp_mst_topology.o.new
26091 0 16 26107 65fb drivers/gpu/drm/drm_dp_mst_topology.o.old
3362 2 0 3364 d24 drivers/gpu/drm/tinydrm/mipi-dbi.o.new
3376 2 0 3378 d32 drivers/gpu/drm/tinydrm/mipi-dbi.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/a78a21b5f34947da65473a0b7326922cda51a3be.1496187315.git.joe@perches.com
When DRM_PANEL is disabled, we get a link error for pl111:
drivers/gpu/built-in.o: In function `pl111_connector_destroy':
pl111_connector.c:(.text+0x3487e6): undefined reference to `drm_panel_detach'
For some reason this only appears in the latest linux-next
although the driver appears to have used the symbol for a few
weeks already. The solution however is simple enough, we just
need to add a 'select' statement.
Fixes: bed41005e6 ("drm/pl111: Initial drm/kms driver for pl111")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170530092224.1204037-1-arnd@arndb.de
Now that we have a callback to check if bridge supports a given mode
we can use it in Analogix bridge so that we restrict the number of
probbed modes to the ones we can actually display.
Also, there is no need to use mode_fixup() callback as mode_valid()
will handle the mode validation.
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1d0ed1858ae56c827bd09cc1fa6ff4a05d1530eb.1495720737.git.joabreu@synopsys.com
This patches makes use of the new mode_valid() callbacks introduced
previously to validate the full video pipeline when modesetting.
This calls the connector->mode_valid(), encoder->mode_valid(),
bridge->mode_valid() and crtc->mode_valid() so that we can
make sure that the mode will be accepted in every components.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Changes v1->v2:
- Removed call to connector->mode_valid (Ville, Daniel)
- Changed function name (Ville)
- Use for_each_new_connector_in_state (Ville)
- Do not validate if connector and mode didn't change (Ville)
- Use new helpers to call mode_valid
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/a457d6a69ad07b3936304653c919068c430c0857.1495720737.git.joabreu@synopsys.com
This changes the connector probe helper function to use the new
encoder->mode_valid(), bridge->mode_valid() and crtc->mode_valid()
helper callbacks to validate the modes.
The new callbacks are optional so the behaviour remains the same
if they are not implemented. If they are, then the code loops
through all the connector's encodersXbridgesXcrtcs and calls the
callback.
If at least a valid encoderXbridgeXcrtc combination is found which
accepts the mode then the function returns MODE_OK.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Changes v3->v4:
- Change function name (Laurent)
Changes v2->v3:
- Call also bridge->mode_valid (Daniel)
Changes v1->v2:
- Use new helpers suggested by Ville
- Change documentation (Daniel)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/d4e3ba87d822fa92f1b8773e441b9a02af3bde71.1495720737.git.joabreu@synopsys.com
Introduce a new helper function which calls mode_valid() callback
for all bridges in an encoder chain.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Archit Taneja <architt@codeaurora.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/36bd5e054496ad3c9c71f1ffe204f28533f55f1e.1495720737.git.joabreu@synopsys.com
Add a new helper to call crtc->mode_valid, connector->mode_valid
and encoder->mode_valid callbacks.
Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Dave Airlie <airlied@linux.ie>
Changes v2->v3:
- Move helpers to drm_probe_helper.c (Daniel)
- Squeeze patches that introduce helpers into a single
one (Daniel)
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
[danvet: Make it compile when CONFIG_DRM_DP_AUX_CHARDEV is selected.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/b55c8bd029da219ff04e39086025c115731a49b1.1495720737.git.joabreu@synopsys.com
This is a leftover from the drm_bus days, where we've had a
bus-specific device type for every bus type in drm_device. Except for
pci (which we can't remove because dri1 drivers) this is all gone. And
the virt driver also doesn't really need it, dev_to_virtio works
perfectly fine.
Cc: David Airlie <airlied@linux.ie>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170524145212.27837-3-daniel.vetter@ffwll.ch
Drop legacy drm_for_each_connector() in favor of the race-free
drm_for_each_connector_iter().
v2: add missing drm_connector_list_iter_end(Daniel Vetter)
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170512164100.7649-1-gustavo@padovan.org
Drop legacy drm_for_each_connector() in favor of the race-free
drm_for_each_connector_iter().
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170511191049.28944-4-gustavo@padovan.org
Drop legacy drm_for_each_connector() in favor of the race-free
drm_for_each_connector_iter()
Cc: Mark Yao <mark.yao@rock-chips.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170515134330.3275-1-gustavo@padovan.org
Constructing the name takes the majority of the time for allocating a
sync_file to wrap a fence, and the name is very rarely used (only via
the sync_file status user interface). To reduce the impact on the common
path (that of creating sync_file to pass around), defer the construction
of the name until it is first used.
v2: Update kerneldoc (kbuild test robot)
v3: sync_debug.c was peeking at the name
v4: Comment upon the potential race between two users of
sync_file_get_name() and claim that such a race is below the level of
notice. However, to prevent any future nuisance, use a global spinlock
to serialize the assignment of the name.
v5: Completely avoid the read/write race by only storing the name passed
in from the user inside sync_file->user_name and passing in a buffer to
dynamically construct the name otherwise.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170516111042.24719-1-chris@chris-wilson.co.uk
Each text file under Documentation follows a different
format. Some doesn't even have titles!
Change its representation to follow the adopted standard,
using ReST markups for it to be parseable by Sphinx:
- Use markup for document title and authorship;
- Mark literal blocks;
- Use a numbered list for references.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/e781f61e582e7c7eb5de456608043aff9fe2b2b5.1495157082.git.mchehab@s-opensource.com
The dead code removal left two unused variables:
drivers/gpu/drm/gma500/mdfld_tpo_vid.c: In function 'tpo_vid_get_config_mode':
drivers/gpu/drm/gma500/mdfld_tpo_vid.c:34:31: error: unused variable 'ti' [-Werror=unused-variable]
This removes them as well.
Fixes: 94d7fb4982 ("gpu: drm: gma500: remove dead code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170522203031.2912874-1-arnd@arndb.de
Brought up by both Laurent and Andrzej when reviewing the new
->mode_valid hooks. Since mode_fixup is just a simpler version of the
much more generic atomic_check we can't really unify it with
mode_valid. Most drivers should probably switch their current
mode_fixup code to either the new mode_valid or the atomic_check
hooks, but e.g. that doesn't exist yet for bridges, and for CRTCs the
situation is a bit more complicated. Hence there's no clear
equivalence between mode_fixup and mode_valid, even if it looks like
that at first glance.
v2: Fix accidental double-dot (Adnrzej).
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170515091136.26307-2-daniel.vetter@ffwll.ch
Laurent started a massive discussion on IRC about this. Let's try to
document common usage a bit better.
v2: Cross-links+typos.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jose Abreu <Jose.Abreu@synopsys.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170515091136.26307-1-daniel.vetter@ffwll.ch
This adds a new callback to crtc, encoder and bridge helper functions
called mode_valid(). This callback shall be implemented if the
corresponding component has some sort of restriction in the modes
that can be displayed. A NULL callback implicates that the component
can display all the modes.
We also change the documentation so that the new and old callbacks
are correctly documented.
Only the callbacks were implemented to simplify review process,
following patches will make use of them.
Changes in v2 from Daniel:
- Update the warning about how modes aren't filtered in atomic_check -
the heleprs help out a lot more now.
- Consistenly roll out that warning, crtc/encoder's atomic_check
missed it.
- Sprinkle more links all over the place, so it's easier to see where
this stuff is used and how the differen hooks are related.
- Note that ->mode_valid is optional everywhere.
- Explain why the connector's mode_valid is special and does _not_ get
called in atomic_check.
v3: Document what can and cannot be checked in mode_valid a bit better
(Andrjez). Answer: Only allowed to look at the mode, nothing else.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v2)
Reviewed-by: Jose Abreu <joabreu@synopsys.com> (v2)
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170515093347.31098-1-daniel.vetter@ffwll.ch
Add Benjamin Gaignard and Vincent Abriou as STM maintainers:
Benjamin Gaignard <benjamin.gaignard@linaro.org>
Vincent Abriou <vincent.abriou@st.com>
Signed-off-by: Vincent Abriou <vincent.abriou@st.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Philippe Cornu <philippe.cornu@st.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1495544446-22360-1-git-send-email-vincent.abriou@st.com
In case of error, the function devm_ioremap_resource() returns ERR_PTR()
and never returns NULL. The NULL test in the return value check should
be replaced with IS_ERR().
Fixes: bed41005e6 ("drm/pl111: Initial drm/kms driver for pl111")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170521010152.6186-1-weiyj.lk@gmail.com
Add DRM_MODE_ROTATE_ and DRM_MODE_REFLECT_ defines to the UAPI
as a convenience.
Ideally the DRM_ROTATE_ and DRM_REFLECT_ property ids are looked up
through the atomic API, but realizing that userspace is likely to take
shortcuts and assume that the enum values are what is sent over the
wire.
As a result these defines are provided purely as a convenience to
userspace applications.
Changes since v3:
- Switched away from past tense in comments
- Add define name change to previously mis-spelled DRM_REFLECT_X comment
- Improved the comment for the DRM_MODE_REFLECT_<axis> comment
Changes since v2:
- Changed define prefix from DRM_MODE_PROP_ to DRM_MODE_
- Fix compilation errors
- Changed comment formatting
- Deduplicated comment lines
- Clarified DRM_MODE_PROP_REFLECT_ comment
Changes since v1:
- Moved defines from drm.h to drm_mode.h
- Changed define prefix from DRM_ to DRM_MODE_PROP_
- Updated uses of the defines to the new prefix
- Removed include from drm_rect.c
- Stopped using the BIT() macro
Signed-off-by: Robert Foss <robert.foss@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519205017.23307-2-robert.foss@collabora.com
In case of error, the function platform_device_register_simple() returns
ERR_PTR() and never returns NULL. The NULL test in the return value
check should be replaced with IS_ERR().
Fixes: af33a9190d ("drm/vgem: Enable dmabuf import interfaces")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Fix fixes: tag per Chris' review.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170521011939.8111-1-weiyj.lk@gmail.com
Include <drm/*.h> instead of relative path from include/drm, then
remove the -Iinclude/drm compiler flag.
While we are here, use <...> instead of "..." for include/linux/*.h
and include/sound/*.h headers too.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1495081793-9707-2-git-send-email-yamada.masahiro@socionext.com
While debugging an X11 display failure, I wanted to see where we were
actually scanning out from. This is probably generally useful to
others that might be working on this device.
v2: Fix uint32_t sparse warning.
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518005640.10310-1-eric@anholt.net
Reviewed-by: Linus Walleij <linus.walleij@linaro.org> (v1)
structure mode_config_funcs can be made static as it does not need to be
in global scope. Fixes sparse warning:
warning: symbol 'mode_config_funcs' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519111018.19641-1-colin.king@canonical.com
structure pl111_display_funcs can be made static as it does not need to be
in global scope. Fixes sparse warning:
"warning: symbol 'pl111_display_funcs' was not declared. Should it
be static?"
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519110203.19417-1-colin.king@canonical.com
This is required for the panel to work on bcm911360, where CLCDCLK is
the fixed 200Mhz AXI41 clock. The rate set is still passed up to the
CLCDCLK, for platforms that have a settable rate on that one.
v2: Set SET_RATE_PARENT (caught by Linus Walleij), depend on
COMMON_CLK.
v3: Mark the clk_ops static (caught by Stephen).
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/20170508193348.30236-1-eric@anholt.net
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Now that drm_[cm]alloc* helpers are simple one line wrappers around
kvmalloc_array and drm_free_large is just kvfree alias we can drop
them and replace by their native forms.
This shouldn't introduce any functional change.
Changes since v1
- fix typo in drivers/gpu//drm/etnaviv/etnaviv_gem.c - noticed by 0day
build robot
Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Michal Hocko <mhocko@suse.com>drm: drop drm_[cm]alloc* helpers
[danvet: Fixup vgem which grew another user very recently.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517122312.GK18247@dhcp22.suse.cz
drm_[cm]alloc* has grown their own kvmalloc with vmalloc fallback
implementations. MM has grown kvmalloc* helpers in the meantime. Let's
use those because it a) reduces the code and b) MM has a better idea
how to implement fallbacks (e.g. do not vmalloc before kmalloc is tried
with __GFP_NORETRY).
drm_calloc_large needs to get __GFP_ZERO explicitly but it is the same
thing as kvmalloc_array in principle.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170517065509.18659-1-mhocko@kernel.org
When IOMMU_IOVA is not built-in but host1x is, we get a link error:
drivers/gpu/host1x/dev.o: In function `host1x_remove':
dev.c:(.text.host1x_remove+0x50): undefined reference to `put_iova_domain'
drivers/gpu/host1x/dev.o: In function `host1x_probe':
dev.c:(.text.host1x_probe+0x31c): undefined reference to `init_iova_domain'
dev.c:(.text.host1x_probe+0x38c): undefined reference to `put_iova_domain'
drivers/gpu/host1x/cdma.o: In function `host1x_cdma_init':
cdma.c:(.text.host1x_cdma_init+0x238): undefined reference to `alloc_iova'
cdma.c:(.text.host1x_cdma_init+0x2c0): undefined reference to `__free_iova'
drivers/gpu/host1x/cdma.o: In function `host1x_cdma_deinit':
cdma.c:(.text.host1x_cdma_deinit+0xb0): undefined reference to `free_iova'
This adds the same select statement that we have for drm_tegra.
Fixes: 404bfb78da ("gpu: host1x: Add IOMMU support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170419182449.885312-1-arnd@arndb.de