Disable atomic on a per-device basis instead of for all devices.
Made possible by the new device.driver_features thing.
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Michel Dänzer <michel@daenzer.net>
Suggested-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180913163147.27900-2-ville.syrjala@linux.intel.com
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Currently we're clearing DRIVER_ATOMIC in driver.driver_features
for older platforms. This will not work correctly should we ever
have a system with and old and new GPU in it. While that is not
possible currently let's make the code more correct and use
the per-device driver_features instead.
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180913131622.17690-2-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
We wish to control certain driver_features flags on a per-device basis
while still sharing a single drm_driver instance across all the
devices. To that end introduce device.driver_features. By default
it will be set to ~0 to not impose any limits beyond
driver.driver_features. Drivers can then clear specific flags
in the per-device bitmask to limit the capabilities of the device.
An alternative approach would be to copy the driver_features from
the driver into the device in drm_dev_init(), however that would
require verifying that no driver is currently changing
driver.driver_features after drm_dev_init(). Hence the ~0 apporach
was easier.
Ideally we'd also make drm_driver const but there is plenty of code
left that wants to mutate it (eg. various vfunc assignments). We'll
need to fix all that up before we can make it const.
And while at it fix up the type of the feature flag passed to
drm_core_check_feature().
v2: Streamline the && vs. & (Chris)
s/int/u32/ in drm_core_check_feature() args
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180913131622.17690-1-ville.syrjala@linux.intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
The Analogix DP bridge driver is pretty verbose, and outputs
things like
[ 619.414067] rockchip-dp ff970000.edp: Link Training Clock Recovery success
[ 619.429233] rockchip-dp ff970000.edp: Link Training success!
each time the display gets unblanked. While it is good to know
that the device is behaving correctly, users already know that
because they can see some video output.
Let's keep these messages for cases where we need to actually
debug the driver (we have dynamic debug to enable them at runtime
if need be), and let's keep the kernel quiet otherwise.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180805172857.2517-1-marc.zyngier@arm.com
Having DRM_SUN4I built-in but DRM_SUN8I_MIXER as a loadable module results in
a link error, as we try to access a symbol from the sun8i_tcon_top.ko module:
ERROR: "sun8i_tcon_top_de_config" [drivers/gpu/drm/sun4i/sun4i-tcon.ko] undefined!
ERROR: "sun8i_tcon_top_set_hdmi_src" [drivers/gpu/drm/sun4i/sun4i-tcon.ko] undefined!
ERROR: "sun8i_tcon_top_of_table" [drivers/gpu/drm/sun4i/sun4i-tcon.ko] undefined!
This solves the problem by adding a silent symbol for the tcon_top module,
building it as a separate module in exactly the cases that we need it,
but in a way that it is reachable by the other modules.
Fixes: cf77d79b4e ("drm/sun4i: tcon: Add another way for matching mixers with tcon")
Fixes: 0305189afb ("drm/sun4i: tcon: Add support for R40 TCON")
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Matt Hart <matthew.hart@linaro.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180911113325.11024-1-maxime.ripard@bootlin.com
Lots of code can be removed by relying on fb-helper:
- "struct drm_framebuffer" moves to fb_helper.fb.
- "struct drm_gem_object" moves to fb_helper.obj[0].
- "struct qxl_device" can be inferred as drm_fb_helper is embedded.
- qxl_user_framebuffer_create -> drm_gem_fb_create.
- qxl_user_framebuffer_destroy -> drm_gem_fb_destroy.
- qxl_fbdev_destroy -> drm_fb_helper_fbdev_teardown + vfree(shadow).
Remove unused code:
- qxl_fbdev_qobj_is_fb, qxl_fbdev_set_suspend.
- Unused fields of qxl_fbdev: delayed_ops, delayed_ops_lock, size.
Misc notes:
- The dirty callback is preserved as it is necessary to trigger update
commands in the hw (the screen stays black otherwise).
- No idea when .create_handle in drm_framebuffer_funcs is used, but use
the same drm_gem_fb_create_handle to match drm_gem_fb_funcs.
- I don't know why qxl_fb_find_or_create_single used to check for an
existing framebuffer and removed that check to match other drivers.
- Use of drm_fb_helper_fbdev_teardown also requires "info->fbdefio" to
be dynamically allocated. Replace the existing defio config by
drm_fb_helper_defio_init to accomodate this.
Testing results: startx with fbdev, modesetting and qxl all seems to
work. Tested also with CONFIG_DRM_FBDEV_EMULATION=n, fbdev obviously
fails but others are fine. QEMU -spice and QEMU -spice with vdagent and
multiple (resized) displays (via remote-viewer) also works.
unbind vtconsole and rmmod has *not* regressed (i.e. it still trips on a
use-after-free in qxl_check_idle via qxl_ttm_fini).
Ideally setup/teardown is replaced by drm_fbdev_generic_setup as that
would result in further code reduction, improve error handling (like not
leaking shadow memory), but unfortunately QXL has no implementation for
qxl_gem_prime_vmap.
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Link: http://patchwork.freedesktop.org/patch/msgid/20180910132156.23201-1-peter@lekensteyn.nl
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Create variable for the list length limit. Serves as documentation,
also allows to make it a module parameter if needed.
Also add a total size limit.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-8-kraxel@redhat.com
udmabuf builds without it, but if userspace can not create memfd
handles in the first place it is rather pointless to include it,
except for test builds.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180911134216.9760-7-kraxel@redhat.com
Add an initial kerneldoc entry for vkms with a todo list.
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
[danvet: Keep the todo.rst entry to point at the vkms docs instead.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907174136.GA2648@haneenDRM
This patch compute CRC for output frame with cursor and primary plane.
Blend cursor with primary plane and compute CRC on the resulted frame.
This currently passes cursor-size-change, and cursor-64x64-[onscreen,
offscreen, sliding, random, dpms, rapid-movement] from igt
kms_cursor_crc tests.
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/b1749f5c90da5721a481f12740e2e370edb4a752.1536210181.git.hamohammed.sa@gmail.com
For buffer sharing, use dma-buf instead. We can't set smem_start to 0
unconditionally since that's used by the fbdev mmap default
implementation. And we have plenty of userspace which would like to
keep that working.
This might break legit userspace - if it does we need to look at a
case-by-cases basis how to handle that. Worst case I expect overrides
for only specific drivers, since anything remotely modern should be
using dma-buf/prime now (which is about 7 years old now for DRM
drivers).
This issue was uncovered because Noralf's rework to implement a
generic fb_probe also implements it's own fb_mmap callback. Which
means smem_start didn't have to be set anymore, which blew up some
blob in userspace rather badly.
Acked-by: Sean Paul <seanpaul@chromium.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-4-daniel.vetter@ffwll.ch
DRM drivers really, really, really don't want random userspace to
share buffer behind it's back, bypassing the dma-buf buffer sharing
machanism. For that reason we've ruthlessly rejected any IOCTL
exposing the physical address of any graphics buffer.
Unfortunately fbdev comes with that built-in. We could just set
smem_start to 0, but that means we'd have to hand-roll our own fb_mmap
implementation. For good reasons many drivers do that, but
smem_start/length is still super convenient.
Hence instead just stop the leak in the ioctl, to keep fb mmap working
as-is. A second patch will set this flag for all drm drivers.
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-3-daniel.vetter@ffwll.ch
It was only used by the panic support in fbcon, which is now gone.
Remove this now dead code too.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joe Perches <joe@perches.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Meng Xu <mengxu.gatech@gmail.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: Mike Frysinger <vapier@chromium.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: David Lechner <david@lechnology.com>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-2-daniel.vetter@ffwll.ch
This was only added for the drm's fbdev emulation support, so that it
would try harder to show the Oops.
Unfortunately this never really worked reliably, and in practice ended
up pushing the real Oops off the screen due to plentyfull locking,
sleep-while-atomic and other issues. So we removed all that support
from the fbdev emulation a while back. Aside: We've also removed the
kgdb support, for similar reasons.
Since it's such a small patch I figured I don't split this up into the
usual 3-phase removal.
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: David Lechner <david@lechnology.com>
Cc: nouveau@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180822085405.10787-1-daniel.vetter@ffwll.ch
DRM_MODE_REFLECT_X and DRM_MODE_REFLECT_Y meaning seems a bit unclear
to me, so try to clarify that with a bit of ascii graphics.
Changes since v1:
- Move the ascii graphics in the kerneldoc where all plane
properties are already documented and make sure it's properly
rendered, suggestested by Daniel Vetter.
Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe@arm.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180910172946.18539-1-alexandru-cosmin.gheorghe@arm.com
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/gpu/drm/drm_plane.c: In function 'drm_mode_getplane_res':
drivers/gpu/drm/drm_plane.c:475:26: warning:
variable 'config' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1536646814-186429-1-git-send-email-yuehaibing@huawei.com
Leaving the DRM driver enabled on reboot or kexec has the annoying
effect of leaving the display generating transactions whilst the
IOMMU has been shut down.
In turn, the IOMMU driver (which shares its interrupt line with
the VOP) starts warning either on shutdown or when entering the
secondary kernel in the kexec case (nothing is expected on that
front).
A cheap way of ensuring that things are nicely shut down is to
register a shutdown callback in the platform driver.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Vicente Bergas <vicencb@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20180805124807.18169-1-marc.zyngier@arm.com
Cc: stable@vger.kernel.org
Clarify the relation between drm_fb_helper_fbdev_setup/teardown. Clarify
requirements for the new generic fbdev emulation API and log some more
details in case the driver does something wrong. Fix related typos.
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180906221810.20170-5-peter@lekensteyn.nl
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Currently unloading bochs_drm (after unbinding the vtconsole) results in
a warning about a leaked connector:
[drm:drm_mode_config_cleanup] *ERROR* connector Virtual-3 leaked!
While investigating a potential fix I noticed that a lot of open-coded
functionality is already implemented elsewhere, so start converting it:
bochs_fbdev_init -> drm_fb_helper_fbdev_setup: trivial (similar impl).
bochs_fbdev_fini -> drm_fb_helper_fbdev_teardown: requires unembedding
"struct drm_framebuffer" from "struct bochs_framebuffer".
Unembedding drm_framebuffer is made easy using drm_gem_fbdev_fb_create
which can replace bochs_fbdev_destroy and custom routines in bochs_mm.c.
For this to work, the GEM object is moved into "drm_framebuffer". After
that, "bochs_framebuffer" is no longer needed and therefore removed.
Remove the unused "size" and "initialized" fields from fb, the latter is
not necessary as drm_fb_helper_fbdev_teardown can be called even if
bochsfb_create fails. This theory was tested by returning early and
late (just before drm_gem_fbdev_fb_create). Both scenarios fail
gracefully although the latter seems to leak the object from
bochsfb_create_object (not a regression).
Guess on the reason for the encoder leak: drm_framebuffer_cleanup was
previously used, but did not destroy much. drm_fb_helper_fbdev_teardown
is now used and calls drm_framebuffer_remove which does a bit more work.
Tested with 'echo 0 > /sys/class/vtconsole/vtcon1/bind; rmmod bochs_drm'
and also with Xorg + fbdev (startx -> xterm). The latter triggered a
warning in ttm_bo_vm_open that existed before, see
https://lkml.kernel.org/r/1464000533-13140-4-git-send-email-mstaudt@suse.de
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Link: http://patchwork.freedesktop.org/patch/msgid/20180906221810.20170-3-peter@lekensteyn.nl
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Drivers must set the quirk_addfb_prefer_host_byte_order quirk to make
the drm_mode_addfb() compat code work correctly on bigendian machines.
If they don't they interpret pixel_format values incorrectly for bug
compatibility, which in turn implies the ADDFB2 ioctl does not work
correctly then. So block it to make userspace fallback to ADDFB.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20180907073213.20410-1-kraxel@redhat.com
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/gpu/drm/virtio/virtgpu_display.c: In function 'virtio_gpu_framebuffer_init':
drivers/gpu/drm/virtio/virtgpu_display.c:78:28: warning:
variable 'bo' set but not used [-Wunused-but-set-variable]
struct virtio_gpu_object *bo;
^
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1536285837-150460-1-git-send-email-yuehaibing@huawei.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This leaves all the commit/check and state handling in drm_atomic.c,
while pulling all the uapi glue and the huge ioctl itself into a
seprate file.
This seems to almost perfectly split the rather big drm_atomic.c file
into 2 equal sizes.
Also adjust the kerneldoc and type a very terse overview text.
v2: Rebase.
v3: Fix tiny typo.
v4:
- Fixup armada, newly converted atomic driver hooray!
- Fixup msm/dpu1, newly added too.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: intel-gfx@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905135711.28370-7-daniel.vetter@ffwll.ch
- drmP.h is now fully split up.
- vkms is happening (and will gain its own todo and docs under a new
vkms.rst file real soon)
- legacy cruft is completely hidden now, drm_vblank.c is split out
from drm_irq.c now. I've decided to drop the task to split out
drm_legacy.ko, partially because Dave already rejected a patch to
hide the old dri1 drivers better. Current state feels good enough to
me.
- best_encoder atomic cleanup is done (it's now the default, not even
exported anymore)
- bunch of smaller things
v2:
- Explain why the drm_legacy.ko task is dropped (Emil).
- typos (Sam).
v3: Fix typo (Ilia)
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905181509.19530-1-daniel.vetter@ffwll.ch
Remove the kerneldoc and EXPORT_SYMBOL which aren't used and really
shouldn't ever be used by drivers directly.
Unfortunately this means we need to move the set_writeback_fb function
around to avoid a forward decl.
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905135711.28370-5-daniel.vetter@ffwll.ch
Only needed minimal changes in drm_internal.h (for the drm_ioctl_t
type and a few forward declarations), plus a few missing includes in
drm_connector.c.
Yay, the last stage of the drm header cleanup can finally commence!
v2: Compiles now, with drm/drm_util.h extracted.
v3: Fix up commit message (Sam Ravnborg)
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905135711.28370-2-daniel.vetter@ffwll.ch
We have a bunch of neat little macros all over the place which should
move to kernel.h. But some of them died in bikesheds on lkml, and we
need a decent home for them.
Start out by moving the for_each_if macro there.
v2: Rename to drm_util.h instead (Dave&Sean)
Cc: Sean Paul <seanpaul@chromium.org>
Acked-by: Sean Paul <seanpaul@chromium.org>
Cc: Dave Airlie <airlied@gmail.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905135711.28370-1-daniel.vetter@ffwll.ch
The hardware supports dithering on TCON channel 0 which is used for LCD
panels.
Dithering is a method of approximating a color from a mixture of other
colors when the required color isn't available. It reduces color
banding artifacts that can be observed when displaying gradients
(e.g. grayscale gradients). This may occur when the image that needs
to be displayed is 24-bit but the LCD panel is a lower bit depth and
does not perform dithering on its own.
Signed-off-by: Jonathan Liu <net147@gmail.com>
[wens@csie.org: check display_info.bpc first; handle LVDS and MIPI DSI]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907041948.19913-4-wens@csie.org
Dithering is only supported for TCON channel 0. Throughout the datasheet
all the names associated with these register are prefixed "TCON0",
instead of "TCON". The only exception is the control register
"TCON_FRM_CTL_REG".
Rename the macros to reflect this.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907041948.19913-3-wens@csie.org
sun4i_tcon0_mode_set_cpu() currently accepts struct mipi_dsi_device *
as its second parameter. This is derived from drm_encoder.
The DSI encoder is tied to the CPU interface mode of the TCON as a
special case. In theory, if hardware were available, we could also
support normal CPU interface modes. It is better to pass the generic
encoder instead of the specialized mipi_dsi_device, and handle the
differences inside the function.
Passing the encoder would also enable the function to pass it, or any
other data structures related to it, to other functions expecting it.
One such example would be dithering support that will be added in a
later patch, which looks at properties tied to the connector to
determine whether dithering should be enabled or not.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180907041948.19913-2-wens@csie.org
we can place a fence to a timeline point after expanded.
v2: change func parameter order
Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/246543/
we can fetch timeline point fence after expanded.
v2: The parameter fence is the result of the function and should come last.
Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/246541/
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