Our current code is supposed to serialise the commits by waiting for all
the drm_crtc_commits associated to the previous HVS state.
However, assuming we have two CRTCs running and being configured and we
configure each one alternately, we end up in a situation where we're
not waiting at all.
Indeed, starting with a state (state 0) where both CRTCs are running,
and doing a commit (state 1) on the first CRTC (CRTC 0), we'll associate
its commit to its assigned FIFO in vc4_hvs_state.
If we get a new commit (state 2), this time affecting the second CRTC
(CRTC 1), the DRM core will allow both commits to execute in parallel
(assuming they don't have any share resources).
Our code in vc4_atomic_commit_tail is supposed to make sure we only get
one commit at a time and serialised by order of submission. It does so
by using for_each_old_crtc_in_state, making sure that the CRTC has a
FIFO assigned, is used, and has a commit pending. If it does, then we'll
wait for the commit before going forward.
During the transition from state 0 to state 1, as our old CRTC state we
get the CRTC 0 state 0, its commit, we wait for it, everything works fine.
During the transition from state 1 to state 2 though, the use of
for_each_old_crtc_in_state is wrong. Indeed, while the code assumes it's
returning the state of the CRTC in the old state (so CRTC 0 state 1), it
actually returns the old state of the CRTC affected by the current
commit, so CRTC 0 state 0 since it wasn't part of state 1.
Due to this, if we alternate between the configuration of CRTC 0 and
CRTC 1, we never actually wait for anything since we should be waiting
on the other every time, but it never is affected by the previous
commit.
Change the logic to, at every commit, look at every FIFO in the previous
HVS state, and if it's in use and has a commit associated to it, wait
for that commit.
Fixes: 9ec03d7f1e ("drm/vc4: kms: Wait on previous FIFO users before a commit")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Tested-by: Jian-Hong Pan <jhp@endlessos.org>
Link: https://lore.kernel.org/r/20211117094527.146275-7-maxime@cerno.tech
Our HVS global state, when duplicated, will also copy the pointer to the
drm_crtc_commit (and increase the reference count) for each FIFO if the
pointer is not NULL.
However, our atomic_setup function will overwrite that pointer without
putting the reference back leading to a memory leak.
Since the commit is only relevant during the atomic commit process, it
doesn't make sense to duplicate the reference to the commit anyway.
Let's remove it.
Fixes: 9ec03d7f1e ("drm/vc4: kms: Wait on previous FIFO users before a commit")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Tested-by: Jian-Hong Pan <jhp@endlessos.org>
Link: https://lore.kernel.org/r/20211117094527.146275-6-maxime@cerno.tech
Commit 9ec03d7f1e ("drm/vc4: kms: Wait on previous FIFO users before a
commit") introduced a wait on the previous commit done on a given HVS
FIFO.
However, we never cleared that pointer once done. Since
drm_crtc_commit_put can free the drm_crtc_commit structure directly if
we were the last user, this means that it can lead to a use-after free
if we were to duplicate the state, and that stale pointer would even be
copied to the new state.
Set the pointer to NULL once we're done with the wait so that we don't
carry over a pointer to a free'd structure.
Fixes: 9ec03d7f1e ("drm/vc4: kms: Wait on previous FIFO users before a commit")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Tested-by: Jian-Hong Pan <jhp@endlessos.org>
Link: https://lore.kernel.org/r/20211117094527.146275-5-maxime@cerno.tech
Commit 9ec03d7f1e ("drm/vc4: kms: Wait on previous FIFO users before a
commit") introduced a global state for the HVS, with each FIFO storing
the current CRTC commit so that we can properly synchronize commits.
However, the refcounting was off and we thus ended up leaking the
drm_crtc_commit structure every commit. Add a drm_crtc_commit_put to
prevent the leakage.
Fixes: 9ec03d7f1e ("drm/vc4: kms: Wait on previous FIFO users before a commit")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Tested-by: Jian-Hong Pan <jhp@endlessos.org>
Link: https://lore.kernel.org/r/20211117094527.146275-4-maxime@cerno.tech
Several DRM/KMS atomic commits can run in parallel if they affect
different CRTC. These commits share the global HVS state, so we have
some code to make sure we run commits in sequence. This synchronization
code is one of the first thing that runs in vc4_atomic_commit_tail().
Another constraints we have is that we need to make sure the HVS clock
gets a boost during the commit. That code relies on clk_set_min_rate and
will remove the old minimum and set a new one. We also need another,
temporary, minimum for the duration of the commit.
The algorithm is thus to set a temporary minimum, drop the previous
one, do the commit, and finally set the minimum for the current mode.
However, the part that sets the temporary minimum and drops the older
one runs before the commit synchronization code.
Thus, under the proper conditions, we can end up mixing up the minimums
and ending up with the wrong one for our current step.
To avoid it, let's move the clock setup in the protected section.
Fixes: d7d96c00e5 ("drm/vc4: hvs: Boost the core clock during modeset")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Tested-by: Jian-Hong Pan <jhp@endlessos.org>
Link: https://lore.kernel.org/r/20211117094527.146275-2-maxime@cerno.tech
The drm_helper_hpd_irq_event() documentation states that this function
is "useful for drivers which can't or don't track hotplug interrupts for
each connector." and that "Drivers which support hotplug interrupts for
each connector individually and which have a more fine-grained detect
logic should bypass this code and directly call
drm_kms_helper_hotplug_event()". This is thus what we ended-up doing.
However, what this actually means, and is further explained in the
drm_kms_helper_hotplug_event() documentation, is that
drm_kms_helper_hotplug_event() should be called by drivers that can
track the connection status change, and if it has changed we should call
that function.
This underlying expectation we failed to provide is that the caller of
drm_kms_helper_hotplug_event() should call drm_helper_probe_detect() to
probe the new status of the connector.
Since we didn't do it, it meant that even though we were sending the
notification to user-space and the DRM clients that something changed we
never probed or updated our internal connector status ourselves.
This went mostly unnoticed since the detect callback usually doesn't
have any side-effect. Also, if we were using the DRM fbdev emulation
(which is a DRM client), or any user-space application that can deal
with hotplug events, chances are they would react to the hotplug event
by probing the connector status eventually.
However, now that we have to enable the scrambler in detect() if it was
enabled it has a side effect, and an application such as Kodi or
modetest doesn't deal with hotplug events. This resulted with a black
screen when Kodi or modetest was running when a screen was disconnected
and then reconnected, or switched off and on.
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210914101724.266570-3-maxime@cerno.tech
drm-misc-next for $kernel-version:
UAPI Changes:
Cross-subsystem Changes:
- dma-buf: Avoid a warning with some allocations, Remove
DMA_FENCE_TRACE macros
Core Changes:
- bridge: New helper to git rid of panels in drivers
- fence: Improve dma_fence_add_callback documentation, Improve
dma_fence_ops->wait documentation
- ioctl: Unexport drm_ioctl_permit
- lease: Documentation improvements
- fourcc: Add new macro to determine the modifier vendor
- quirks: Add the Steam Deck, Chuwi HiBook, Chuwi Hi10 Pro, Samsung
Galaxy Book 10.6, KD Kurio Smart C15200 2-in-1, Lenovo Ideapad D330
- resv: Improve the documentation
- shmem-helpers: Allocate WC pages on x86, Switch to vmf_insert_pfn
- sched: Fix for a timer being canceled too soon, Avoid null pointer
derefence if the fence is null in drm_sched_fence_free, Convert
drivers to rely on its dependency tracking
- ttm: Switch to kerneldoc, new helper to clear all DMA mappings, pool
shrinker optitimization, Remove ttm_tt_destroy_common, Fix for
unbinding on multiple drivers
Driver Changes:
- bochs: New PCI IDs
- msm: Fence ordering impromevemnts
- stm: Add layer alpha support, zpos
- v3d: Fix for a Vulkan CTS failure
- vc4: Conversion to the new bridge helpers
- vgem: Use shmem helpers
- virtio: Support mapping exported vram
- zte: Remove obsolete driver
- bridge: Probe improvements for it66121, enable DSI EOTP for anx7625,
errors propagation improvements for anx7625
- panels: 60fps mode for otm8009a, New driver for Samsung S6D27A1
Signed-off-by: Dave Airlie <airlied@redhat.com>
# gpg: Signature made Thu 16 Sep 2021 17:30:50 AEST
# gpg: using EDDSA key 5C1337A45ECA9AEB89060E9EE3EF0D6F671851C5
# gpg: Can't check signature: No public key
From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210916073132.ptbbmjetm7v3ufq3@gilmour
Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
don't benefit from using it.
DRM IRQ callbacks are now being called directly or inlined.
Calls to platform_get_irq() can fail with a negative errno code.
Abort initialization in this case. The DRM IRQ midlayer does not
handle this case correctly.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210803090704.32152-13-tzimmermann@suse.de
drm-misc-next for v5.15:
UAPI Changes:
- Add modifiers for arm fixed rate compression.
Cross-subsystem Changes:
- Assorted dt binding fixes.
- Convert ssd1307fb to json-schema.
- Update a lot of irc channels to point to OFTC, as everyone moved there.
- Fix the same divide by zero for asilantfb, kyro, rivafb.
Core Changes:
- Document requirements for new atomic properties.
- Add drm_gem_fb_(begin/end)_cpu_access helpers, and use them in some drivers.
- Document drm_property_enum.value for bitfields.
- Add explicit _NO_ for MIPI_DSI flags that disable features.
- Assorted documentation fixes.
- Update fb_damage handling, and move drm_plane_enable_fb_damage_clips to core.
- Add logging and docs to RMFB ioctl.
- Assorted small fixes to dp_mst, master handling.
- Clarify drm lease usage.
Driver Changes:
- Assorted small fixes to panfrost, hibmc, bridge/nwl-dsi, rockchip, vc4.
- More drm -> linux irq conversions.
- Add support for some Logic Technologies and Multi-Inno panels.
- Expose phy-functionality for drm/rockchip, to allow controlling from the media subsystem.
- Add support for 2 AUO panels.
- Add damage handling to ssd1307fb.
- Improve FIFO handling on mxsfb.
- Assorted small fixes to vmwgfx, and bump version to 2.19 for the new ioctls.
- Improve sony acx424akp backlight handling.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a753221a-e23e-0dc4-7ca6-8c1b179738d0@linux.intel.com
The vc4_hdmi_audio_prepare function and the functions it's calling have
in several occurences multiple dereferences of either the sample rate or
the number of channels.
It turns out that these variables are also passed through the hdmi codec
parameters structure. Convert all the users to use this structure, and
if it's used multiple times use a variable to store it instead of
dereferencing it every time.
Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210707093632.1468127-1-maxime@cerno.tech
