This is the new API for allocating DRM bridges.
This driver already implements refcounting of the struct vc4_dsi, which
embeds struct drm_bridge. Now this is a duplicate of the refcounting
implemented by the DRM bridge core, so convert the vc4_dsi_get/put() calls
into drm_bridge_get/put() calls and get rid of the driver-specific
refcounting implementation.
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250424-drm-bridge-convert-to-alloc-api-v2-27-8f91a404d86b@bootlin.com
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
The drm_bridge structure contains an encoder pointer that is widely used
by bridge drivers. This pattern is largely documented as deprecated in
other KMS entities for atomic drivers.
However, one of the main use of that pointer is done in attach to just
call drm_bridge_attach on the next bridge to add it to the bridge list.
While this dereferences the bridge->encoder pointer, it's effectively
the same encoder the bridge was being attached to.
We can make it more explicit by adding the encoder the bridge is
attached to to the list of attach parameters. This also removes the need
to dereference bridge->encoder in most drivers.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250313-bridge-connector-v6-1-511c54a604fb@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
It's pretty inconvenient to access the full atomic state from
drm_bridges, so let's change the atomic_post_disable hook prototype to
pass it directly.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250213-bridge-connector-v3-5-e71598f49c8f@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
It's pretty inconvenient to access the full atomic state from
drm_bridges, so let's change the atomic_disable hook prototype to pass
it directly.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250213-bridge-connector-v3-4-e71598f49c8f@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
It's pretty inconvenient to access the full atomic state from
drm_bridges, so let's change the atomic_enable hook prototype to pass it
directly.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250213-bridge-connector-v3-3-e71598f49c8f@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
It's pretty inconvenient to access the full atomic state from
drm_bridges, so let's change the atomic_pre_enable hook prototype to
pass it directly.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250213-bridge-connector-v3-2-e71598f49c8f@kernel.org
Signed-off-by: Maxime Ripard <mripard@kernel.org>
The continual trickle of small conversion patches is grating on me, and
is really not helping. Just get rid of the 'remove_new' member
function, which is just an alias for the plain 'remove', and had a
comment to that effect:
/*
* .remove_new() is a relic from a prototype conversion of .remove().
* New drivers are supposed to implement .remove(). Once all drivers are
* converted to not use .remove_new any more, it will be dropped.
*/
This was just a tree-wide 'sed' script that replaced '.remove_new' with
'.remove', with some care taken to turn a subsequent tab into two tabs
to make things line up.
I did do some minimal manual whitespace adjustment for places that used
spaces to line things up.
Then I just removed the old (sic) .remove_new member function, and this
is the end result. No more unnecessary conversion noise.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DRM_ERROR() has been deprecated in favor of pr_err(). However, we
should prefer to use drm_err() whenever possible so we get device-
specific output with the error message. In error case of kcalloc,
we can simply drop DRM_ERROR(), because kcalloc already logs errors.
Suggested-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240821214052.6800-4-wahrenst@gmx.net
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230714174545.4056287-1-robh@kernel.org
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.
Trivially convert the vc4 drm drivers from always returning zero in the
remove callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230507162616.1368908-53-u.kleine-koenig@pengutronix.de
container_of_const() allows to preserve the pointer constness and is
thus more flexible than inline functions.
Let's switch all our instances of container_of() to
container_of_const().
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20221207-rpi-hdmi-improvements-v3-1-bdd54f66884e@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The bridge->of_node field is defined inside of an #ifdef, which
results in a build failure when compile-testing the vc4_dsi driver
without CONFIG_OF:
drivers/gpu/drm/vc4/vc4_dsi.c: In function 'vc4_dsi_dev_probe':
drivers/gpu/drm/vc4/vc4_dsi.c:1822:20: error: 'struct drm_bridge' has no member named 'of_node'
1822 | dsi->bridge.of_node = dev->of_node;
Add another #ifdef in the place it is used in. Alternatively we
could consider dropping the #ifdef in the struct definition
and all other users.
Fixes: 78df640394 ("drm/vc4: dsi: Convert to using a bridge instead of encoder")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20230117165258.1979922-1-arnd@kernel.org
Currently, vc4 has its own debugfs infrastructure that adds the debugfs
files on drm_dev_register(). With the introduction of the new debugfs,
functions, replace the vc4 debugfs structure with the DRM debugfs
device-centered function, drm_debugfs_add_file().
Moreover, remove the explicit error handling of debugfs related functions,
considering that the only failure mode is -ENOMEM and also that error
handling is not recommended for debugfs functions, as pointed out in [1].
[1] https://lore.kernel.org/all/YWAmZdRwnAt6wh9B@kroah.com/
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20221219120621.15086-5-mcanal@igalia.com
Post_disable was sending the D-PHY sequence to put any device
into ULPS suspend mode, and then cutting power to the DSI block.
The power-on reset state of the DSI block is for DSI to be in
an operational state, not ULPS, so it then never sent the sequence
for exiting ULPS. Any attached device that didn't have an external
reset therefore remained in ULPS / standby, and didn't function.
Use of ULPS isn't well specified in DRM, therefore remove entering
it to avoid the above situation.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-dsi-bridge-v1-6-8f68ee0b0adb@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Remove the encoder functions, and create a bridge attached to
this dumb encoder which implements the same functionality.
As a bridge has state which an encoder doesn't, we need to
add the state management functions as well.
As there is no bridge atomic_mode_set, move the initialisation
code that was in mode_set into _pre_enable.
The code to actually enable and disable sending video are split
from the general control into _enable and _disable.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-dsi-bridge-v1-5-8f68ee0b0adb@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The atomic calls are preferred as the non-atomic ones
are deprecated. In preparation for conversion to a bridge,
switch to the atomic calls.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-dsi-bridge-v1-4-8f68ee0b0adb@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Splitting the bridge chain fails for atomic bridges as the
framework can't add the relevant state in
drm_atomic_add_encoder_bridges.
The chain was split because we needed to power up before
calling pre_enable, but that is now done in mode_set, and will
move into the framework.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-dsi-bridge-v1-3-8f68ee0b0adb@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Breaking the bridge chain does not work for atomic bridges/panels
and generally causes issues.
We need to initialise the DSI host before the bridge pre_enables
are called, so move that to encoder_mode_set in the same way that
dw-mipi-dsi does.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-dsi-bridge-v1-2-8f68ee0b0adb@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
In preparation for converting the encoder to being a bridge,
rename the variable holding the next bridge in the chain to
out_bridge, so that our bridge can be called bridge.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20221207-rpi-dsi-bridge-v1-1-8f68ee0b0adb@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Accessing a register when running under kunit is a bad idea since our
device is completely mocked.
Fail the current test if we ever access any of our hardware registers.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-18-4615a663a84a@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The vc4 has a custom API to allow components to register a debugfs file
before the DRM driver has been registered and the debugfs_init hook has
been called.
However, the .late_register hook allows to have the debugfs file creation
deferred after that time already.
Let's remove our custom code to only register later our debugfs entries as
part of either debugfs_init or after it.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-65-maxime@cerno.tech
devm_pm_runtime_enable() simplifies the driver a bit since it will call
pm_runtime_disable() automatically through a device-managed action.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-37-maxime@cerno.tech
The vc4_dsi structure is currently allocated through a device-managed
allocation. This can lead to use-after-free issues however in the unbinding
path since the DRM entities will stick around, but the underlying structure
has been freed.
However, we can't just fix it by using a DRM-managed allocation like we did
for the other drivers since the DSI case is a bit more intricate.
Indeed, the structure will be allocated at probe time, when we don't have a
DRM device yet, to be able to register the DSI bus driver. We will then
reuse it at bind time to register our KMS entities in the framework.
In order to work around both constraints, we can use a kref to track the
users of the structure (DSI host, and KMS), and then put our structure when
the DSI host will have been unregistered, and through a DRM-managed action
that will execute once we won't need the KMS entities anymore.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-36-maxime@cerno.tech
The current code uses a device-managed function to retrieve the next bridge
downstream.
However, that means that it will be removed at unbind time, where the DRM
device is still very much live and might still have some applications that
still have it open.
Switch to a DRM-managed variant to clean everything up once the DRM device
has been last closed.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-35-maxime@cerno.tech
The current code will call drm_encoder_cleanup() when the device is
unbound. However, by then, there might still be some references held to
that encoder, including by the userspace that might still have the DRM
device open.
Let's switch to a DRM-managed initialization to clean up after ourselves
only once the DRM device has been last closed.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-34-maxime@cerno.tech
The VC4 DSI driver private structure contains only a pointer to the
encoder it implements. This makes the overall structure somewhat
inconsistent with the rest of the driver, and complicates its
initialisation without any apparent gain.
Let's embed the drm_encoder structure (through the vc4_encoder one) into
struct vc4_dsi to fix both issues.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-33-maxime@cerno.tech
vc4_dsi_encoder_disable is partially an open coded version of
drm_bridge_chain_disable, but it missed a termination condition
in the loop for ->disable which meant that no post_disable
calls were made.
Add in the termination clause.
Fixes: 033bfe7538 ("drm/vc4: dsi: Fix bridge chain handling")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-17-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
DSI0 seemingly had very little or no testing as a load of
the register mappings were incorrect/missing, so host
transfers always timed out due to enabling/checking incorrect
bits in the interrupt enable and status registers.
Fixes: 4078f57571 ("drm/vc4: Add DSI driver")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-16-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
vc4_dsi was registering both dsi0 and dsi1 as VC4_ENCODER_TYPE_DSI1
which seemed to work OK for a single DSI display, but fails
if there are two DSI displays connected.
Update to register the correct type.
Fixes: 4078f57571 ("drm/vc4: Add DSI driver")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-15-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The divider calculations tried to find the divider just faster than the
clock requested. However if it required a divider of 7 then the for loop
aborted without handling the "error" case, and could end up with a clock
lower than requested.
The integer divider from parent PLL to DSI clock is also capable of
going up to /255, not just /7 that the driver was trying. This allows
for slower link frequencies on the DSI bus where the resolution permits.
Correct the loop so that we always have a clock greater than requested,
and covering the whole range of dividers.
Fixes: 86c1b9eff3 ("drm/vc4: Adjust modes in DSI to work around the integer PLL divider.")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-13-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
On Pi0-3 the driver allocates a buffer and requests a DMA channel
because the ARM can't write to DSI1's registers directly.
However, we never release that buffer or channel. Let's add a
device-managed action to release each.
Fixes: 4078f57571 ("drm/vc4: Add DSI driver")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-12-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
If the device is already in a runtime PM enabled state
pm_runtime_get_sync() will return 1.
Also, we need to call pm_runtime_put_noidle() when pm_runtime_get_sync()
fails, so use pm_runtime_resume_and_get() instead. this function
will handle this.
Fixes: 4078f57571 ("drm/vc4: Add DSI driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220420135008.2757-1-linmq006@gmail.com
Being informed of a failure to attach a bridge is useful, and many
drivers prints an error message in that case. Move the message to
drm_bridge_attach() to avoid code duplication.
Suggested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Jyri Sarha <jyri.sarha@iki.fi>
BCM2711 DSI1 doesn't have the issue with the ARM not being
able to write to the registers, therefore remove the DMA
workaround for that compatible string.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203132543.861591-8-maxime@cerno.tech
DSI0 was partially supported, but didn't register with the main
driver, and the code was inconsistent as to whether it checked
port == 0 or port == 1.
Add compatible string and other support to make it consistent.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203132543.861591-6-maxime@cerno.tech
Most of the differences between DSI0 and DSI1 are handled through the
ID. However, the BCM2711 DSI is going to introduce one more variable to
the mix and will break some expectations of the earlier, simpler, test.
Let's add a variant structure that will address most of the differences
between those three controllers.
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203132543.861591-5-maxime@cerno.tech
The DSI clocks setup function has been using an array to store the clock
name of either the DSI0 or DSI1 blocks, using the port ID to choose the
proper one.
Let's switch to an snprintf call to do the same thing and simplify the
array a bit.
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203132543.861591-4-maxime@cerno.tech
The DSI1_PHY_AFEC0_PD_DLANE1 and DSI1_PHY_AFEC0_PD_DLANE3 register
definitions were swapped, so trying to use more than a single data
lane failed as lane 1 would get powered down.
(In theory a 4 lane device would work as all lanes would remain
powered).
Correct the definitions.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203132543.861591-3-maxime@cerno.tech
If the DSI driver is the last to probe, component_add will try to run all
the bind callbacks straight away and return the error code.
However, since we depend on a power domain, we're pretty much guaranteed to
be in that case on the BCM2711, and are just lucky on the previous SoCs
since the v3d also depends on that power domain and is further in the probe
order.
In that case, the DSI host will not stick around in the system: the DSI
bind callback will be executed, will not find any DSI device attached and
will return EPROBE_DEFER, and we will then remove the DSI host and ask to
be probed later on.
But since that host doesn't stick around, DSI devices like the RaspberryPi
touchscreen whose probe is not linked to the DSI host (unlike the usual DSI
devices that will be probed through the call to mipi_dsi_host_register)
cannot attach to the DSI host, and we thus end up in a situation where the
DSI host cannot probe because the panel hasn't probed yet, and the panel
cannot probe because the DSI host hasn't yet.
In order to break this cycle, let's wait until there's a DSI device that
attaches to the DSI host to register the component and allow to progress
further.
Acked-by: Eric Anholt <eric@anholt.net>
Suggested-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20200707101912.571531-1-maxime@cerno.tech
The vc4 driver uses empty implementations for its encoders. Replace
the code with the generic simple encoder.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200305155950.2705-19-tzimmermann@suse.de
Most bridge drivers create a DRM connector to model the connector at the
output of the bridge. This model is historical and has worked pretty
well so far, but causes several issues:
- It prevents supporting more complex display pipelines where DRM
connector operations are split over multiple components. For instance a
pipeline with a bridge connected to the DDC signals to read EDID data,
and another one connected to the HPD signal to detect connection and
disconnection, will not be possible to support through this model.
- It requires every bridge driver to implement similar connector
handling code, resulting in code duplication.
- It assumes that a bridge will either be wired to a connector or to
another bridge, but doesn't support bridges that can be used in both
positions very well (although there is some ad-hoc support for this in
the analogix_dp bridge driver).
In order to solve these issues, ownership of the connector should be
moved to the display controller driver (where it can be implemented
using helpers provided by the core).
Extend the bridge API to allow disabling connector creation in bridge
drivers as a first step towards the new model. The new flags argument to
the bridge .attach() operation allows instructing the bridge driver to
skip creating a connector. Unconditionally set the new flags argument to
0 for now to keep the existing behaviour, and modify all existing bridge
drivers to return an error when connector creation is not requested as
they don't support this feature yet.
The change is based on the following semantic patch, with manual review
and edits.
@ rule1 @
identifier funcs;
identifier fn;
@@
struct drm_bridge_funcs funcs = {
...,
.attach = fn
};
@ depends on rule1 @
identifier rule1.fn;
identifier bridge;
statement S, S1;
@@
int fn(
struct drm_bridge *bridge
+ , enum drm_bridge_attach_flags flags
)
{
... when != S
+ if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
+ DRM_ERROR("Fix bridge driver to make connector optional!");
+ return -EINVAL;
+ }
+
S1
...
}
@ depends on rule1 @
identifier rule1.fn;
identifier bridge, flags;
expression E1, E2, E3;
@@
int fn(
struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags
) {
<...
drm_bridge_attach(E1, E2, E3
+ , flags
)
...>
}
@@
expression E1, E2, E3;
@@
drm_bridge_attach(E1, E2, E3
+ , 0
)
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-10-laurent.pinchart@ideasonboard.com
Commit 05193dc381 ("drm/bridge: Make the bridge chain a double-linked
list") patched the bridge chain logic to use a double-linked list instead
of a single-linked list. This change induced changes to the VC4 driver
which was manually resetting the encoder->bridge element to NULL to
control the enable/disable sequence of the bridge chain. During this
conversion, 2 bugs were introduced:
1/ list_splice() was used to move chain elements to our own internal
chain, but list_splice() does not reset the source list to an empty
state, leading to unexpected bridge hook calls when
drm_bridge_chain_xxx() helpers were called by the core. Replacing
those list_splice() calls by list_splice_init() ones fixes this
problem.
2/ drm_bridge_chain_xxx() helpers operate on the
bridge->encoder->bridge_chain list, which is now empty. When the
helper uses list_for_each_entry_reverse() we end up with no operation
done which is not what we want. But that's even worse when the helper
uses list_for_each_entry_from(), because in that case we end up in
an infinite loop searching for the list head element which is no
longer encoder->bridge_chain but vc4_dsi->bridge_chain. To address
that problem we stop using the bridge chain helpers and call the
hooks directly.
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Eric Anholt <eric@anholt.net>
Fixes: 05193dc381 ("drm/bridge: Make the bridge chain a double-linked list")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20191227144124.210294-2-boris.brezillon@collabora.com
So that each element in the chain can easily access its predecessor.
This will be needed to support bus format negotiation between elements
of the bridge chain.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-5-boris.brezillon@collabora.com
Change the prefix of bridge helpers targeting a bridge chain from
drm_bridge_ to drm_bridge_chain_ to better reflect the fact that
the operation will happen on all elements of chain, starting at the
bridge passed in argument.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-2-boris.brezillon@collabora.com
The drm panel bridge creates a connector using a connector type
explicitly passed by the display controller or bridge driver that
instantiates the panel bridge. Now that drm_panel reports its connector
type, we can use it to avoid passing an explicit (and often incorrect)
connector type to drm_panel_bridge_add() and
devm_drm_panel_bridge_add().
Several drivers report incorrect or unknown connector types to
userspace. Reporting a different type may result in a breakage. For that
reason, rename (devm_)drm_panel_bridge_add() to
(devm_)drm_panel_bridge_add_typed(), and add new
(devm_)drm_panel_bridge_add() functions that use the panel connector
type. Update all callers of (devm_)drm_panel_bridge_add() to the _typed
function, they will be converted one by one after testing.
The panel drivers have been updated with the following Coccinelle
semantic patch, with manual inspection and fixes to indentation.
@@
expression bridge;
expression dev;
expression panel;
identifier type;
@@
(
-bridge = drm_panel_bridge_add(panel, type);
+bridge = drm_panel_bridge_add_typed(panel, type);
|
-bridge = devm_drm_panel_bridge_add(dev, panel, type);
+bridge = devm_drm_panel_bridge_add_typed(dev, panel, type);
)
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190904132804.29680-3-laurent.pinchart@ideasonboard.com
