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/20220711173939.1132294-30-maxime@cerno.tech
Our internal structure that stores the DRM entities structure is allocated
through a device-managed kzalloc.
This means that this will eventually be freed whenever the device is
removed. In our case, the most likely source of removal is that the main
device is going to be unbound, and component_unbind_all() is being run.
However, it occurs while the DRM device is still registered, which will
create dangling pointers, eventually resulting in use-after-free.
Switch to a DRM-managed allocation to keep our structure until the DRM
driver doesn't need it anymore.
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/20220711173939.1132294-26-maxime@cerno.tech
The VC4 DPI 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_dpi to fix both issues.
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/20220711173939.1132294-25-maxime@cerno.tech
The current code will call drm_crtc_cleanup() when the device is
unbound. However, by then, there might still be some references held to
that CRTC, 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/20220711173939.1132294-23-maxime@cerno.tech
Our internal structure that stores the DRM entities structure is allocated
through a device-managed kzalloc.
This means that this will eventually be freed whenever the device is
removed. In our case, the most likely source of removal is that the main
device is going to be unbound, and component_unbind_all() is being run.
However, it occurs while the DRM device is still registered, which will
create dangling pointers, eventually resulting in use-after-free.
Switch to a DRM-managed allocation to keep our structure until the DRM
driver doesn't need it anymore.
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/20220711173939.1132294-22-maxime@cerno.tech
When vc4_crtc_bind() fails after vc4_crtc_init() has been called, we have
a loop undoing the plane creation and calling destroy on each plane
registered and matching the possible_crtcs mask.
However, this is redundant with what drm_mode_config_cleanup() is doing, so
let's remove it.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-19-maxime@cerno.tech
When the HVS driver is unbound, a lot of memory allocations in the LBM and
DLIST RAM are still assigned to planes that are still allocated.
Thus, we hit a warning when calling drm_mm_takedown() since the memory pool
is not completely free of allocations.
Let's free all the currently live entries before calling drm_mm_takedown().
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/20220711173939.1132294-17-maxime@cerno.tech
Whenever the device and driver are unbound, the main device and all the
subdevices will be removed by calling their unbind() method.
However, the DRM device itself will only be freed when the last user will
have closed it.
It means that there is a time window where the device and its resources
aren't there anymore, but the userspace can still call into our driver.
Fortunately, the DRM framework provides the drm_dev_enter() and
drm_dev_exit() functions to make sure our underlying device is still there
for the section protected by those calls. Let's add them to the HVS driver.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-16-maxime@cerno.tech
When our KMS driver is unbound, the device is no longer there but we might
still have users with an opened fd to the KMS device.
To avoid any issue in such a situation, every device access needs to be
protected by calls to drm_dev_enter() and drm_dev_exit(), and the driver
needs to call drm_dev_unplug().
We'll add calls to drm_dev_enter()/drm_dev_exit() in subsequent patches
changing the relevant drivers, but let's start by calling drm_dev_unplug().
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-14-maxime@cerno.tech
The current code tries to handle the case where CONFIG_PM isn't selected
by first calling our runtime_resume implementation and then properly
report the power state to the runtime_pm core.
This allows to have a functionning device even if pm_runtime_get_*
functions are nops.
However, the device power state if CONFIG_PM is enabled is
RPM_SUSPENDED, and thus our vc4_hdmi_write() and vc4_hdmi_read() calls
in the runtime_pm hooks will now report a warning since the device might
not be properly powered.
Even more so, we need CONFIG_PM enabled since the previous RaspberryPi
have a power domain that needs to be powered up for the HDMI controller
to be usable.
The previous patch has created a dependency on CONFIG_PM, now we can
just assume it's there and only call pm_runtime_resume_and_get() to make
sure our device is powered in bind.
Link: https://lore.kernel.org/r/20220629123510.1915022-39-maxime@cerno.tech
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
With the change to 2 pixels/clock, the pixel doubling in the PV
results in doubling each pair of pixels, ie ABABCDCD instead of
AABBCCDD.
Move the pixel doubling to the HDMI block, however this means
that DBLCLK modes now fall foul of requiring even values for
all the horizontal timing parameters.
As both 480i and 576i fail this, attempt to fix up DBLCLK modes
that have odd timings values.
Fixes: 8323989140 ("drm/vc4: hdmi: Support the BCM2711 HDMI controllers")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-34-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Whenever the maximum BPC is changed, vc4_hdmi_encoder_compute_config()
might pick up a different BPC or format depending on the display
capabilities.
That change will have a number of side effects, including the clock
rates and whether the scrambling is enabled.
However, only drm_crtc_state.connectors_changed will be set to true,
since that properly only affects the connector.
This means that while drm_atomic_crtc_needs_modeset() will return true,
and thus drm_atomic_helper_commit_modeset_enables() will call our
encoder atomic_enable() hook, mode_changed will be false.
So crtc_set_mode() will not call our encoder .atomic_mode_set() hook. We
use this hook in vc4 to set the vc4_hdmi_connector_state.output_bpc (and
output_format), and will then reuse the value in .atomic_enable() to select
whether or not scrambling should be enabled.
However, since our clock rate is pre-computed during .atomic_check(), we
end up with the clocks properly configured, but the scrambling disabled,
leading to a blank screen.
Let's set mode_changed to true in our HDMI driver to force the update of
output_bpc, and thus prevent the issue entirely.
Fixes: ba8c0faebb ("drm/vc4: hdmi: Enable 10/12 bpc output")
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Link: https://lore.kernel.org/r/20220613144800.326124-32-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Increase the number of post-sync blanking lines on odd fields instead of
decreasing it on even fields. This makes the total number of lines
properly match the modelines.
Additionally fix the value of PV_VCONTROL_ODD_DELAY, which did not take
pixels_per_clock into account, causing some displays to invert the
fields when driven by bcm2711.
Fixes: 682e62c454 ("drm/vc4: Fix support for interlaced modes on HDMI.")
Signed-off-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Link: https://lore.kernel.org/r/20220613144800.326124-31-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The current HDMI driver, in vc4_hdmi_audio_can_stream() checks whether
the display output is enabled.
This has been there in one form or the other since the introduction of
the audio support in the VC4 HDMI driver in commit bb7d785688
("drm/vc4: Add HDMI audio support"), but no justification for this check
is in the commit message, or in the discussions around the patches.
One can only assume this was done to prevent a user from playing audio
on the ALSA soundcard when the monitor doesn't support it.
However, this is causing some issues. Indeed, Kodi, for example, was
hitting some errors if it was streaming audio during a modeset. With the
theory above, it does make sense, but the display and audio threads are
typically completely different processes with no opportunity to
synchronise which makes it hard to workaround.
Removing that check also doesn't seem to cause any trouble, so let's
just remove it.
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
Link: https://lore.kernel.org/r/20220613144800.326124-25-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The BCM2835-37 found in the RaspberryPi 0 to 3 have a power domain
attached to the HDMI block, handled in Linux through runtime_pm.
That power domain is shared with the VEC block, so even if we put our
runtime_pm reference in the HDMI driver it would keep being on. If the
VEC is disabled though, the power domain would be disabled and we would
lose any initialization done in our bind implementation.
That initialization involves calling the reset function and initializing
the CEC registers.
Let's move the initialization to our runtime_resume implementation so
that we initialize everything properly if we ever need to.
Fixes: c86b412143 ("drm/vc4: hdmi: Move the HSM clock enable to runtime_pm")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-24-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
If the controller isn't clocked or its domain powered up, the register
accesses will either stall the CPU or return garbage, respectively.
Thus, we had a warning in our register access function to complain when
that kind of risky accesses were performed.
In order to check the runtime_pm power state, we were using
pm_runtime_active(), but it turns out that it will become active only
once the runtime_resume hook has been executed.
This prevents us from doing any WARN-free register access in our
runtime_resume() implementation, while this is valid.
Let's switch to pm_runtime_status_suspended() instead.
Fixes: 14e193b956 ("drm/vc4: hdmi: Warn if we access the controller while disabled")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-23-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The HDMI block can repeat pixels for double clocked modes,
and the firmware is now configuring the block to do this as
the PV is doing it incorrectly when at 2pixels/clock.
If the kernel doesn't reset it then we end up with strange
modes.
Reset MISC_CONTROL.
Fixes: 8323989140 ("drm/vc4: hdmi: Support the BCM2711 HDMI controllers")
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-22-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
The dmas property is used to hold the dmaengine channel used for audio
output.
Older device trees were missing that property, so if it's not there we
disable the audio output entirely.
However, some overlays have set an empty value to that property, mostly
to workaround the fact that overlays cannot remove a property. Let's add
a test for that case and if it's empty, let's disable it as well.
Cc: <stable@vger.kernel.org>
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
Link: https://lore.kernel.org/r/20220613144800.326124-18-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>
