Now that we've finally gotten rid of the non-atomic MST users leftover in
the kernel, we can finally get rid of all of the legacy payload code we
have and move as much as possible into the MST atomic state structs. The
main purpose of this is to make the MST code a lot less confusing to work
on, as there's a lot of duplicated logic that doesn't really need to be
here. As well, this should make introducing features like fallback link
retraining and DSC support far easier.
Since the old payload code was pretty gnarly and there's a Lot of changes
here, I expect this might be a bit difficult to review. So to make things
as easy as possible for reviewers, I'll sum up how both the old and new
code worked here (it took me a while to figure this out too!).
The old MST code basically worked by maintaining two different payload
tables - proposed_vcpis, and payloads. proposed_vcpis would hold the
modified payload we wanted to push to the topology, while payloads held the
payload table that was currently programmed in hardware. Modifications to
proposed_vcpis would be handled through drm_dp_allocate_vcpi(),
drm_dp_mst_deallocate_vcpi(), and drm_dp_mst_reset_vcpi_slots(). Then, they
would be pushed via drm_dp_mst_update_payload_step1() and
drm_dp_mst_update_payload_step2().
Furthermore, it's important to note how adding and removing VC payloads
actually worked with drm_dp_mst_update_payload_step1(). When a VC payload
is removed from the VC table, all VC payloads which come after the removed
VC payload's slots must have their time slots shifted towards the start of
the table. The old code handles this by looping through the entire payload
table and recomputing the start slot for every payload in the topology from
scratch. While very much overkill, this ends up doing the right thing
because we always order the VCPIs for payloads from first to last starting
timeslot.
It's important to also note that drm_dp_mst_update_payload_step2() isn't
actually limited to updating a single payload - the driver can use it to
queue up multiple payload changes so that as many of them can be sent as
possible before waiting for the ACT. This is -technically- not against
spec, but as Wayne Lin has pointed out it's not consistently implemented
correctly in hubs - so it might as well be.
drm_dp_mst_update_payload_step2() is pretty self explanatory and basically
the same between the old and new code, save for the fact we don't have a
second step for deleting payloads anymore -and thus rename it to
drm_dp_mst_add_payload_step2().
The new payload code stores all of the current payload info within the MST
atomic state and computes as much of the state as possible ahead of time.
This has the one exception of the starting timeslots for payloads, which
can't be determined at atomic check time since the starting time slots will
vary depending on what order CRTCs are enabled in the atomic state - which
varies from driver to driver. These are still stored in the atomic MST
state, but are only copied from the old MST state during atomic commit
time. Likewise, this is when new start slots are determined.
Adding/removing payloads now works much more closely to how things are
described in the spec. When we delete a payload, we loop through the
current list of payloads and update the start slots for any payloads whose
time slots came after the payload we just deleted. Determining the starting
time slots for new payloads being added is done by simply keeping track of
where the end of the VC table is in
drm_dp_mst_topology_mgr->next_start_slot. Additionally, it's worth noting
that we no longer have a single update_payload() function. Instead, we now
have drm_dp_mst_add_payload_step1|2() and drm_dp_mst_remove_payload(). As
such, it's now left it up to the driver to figure out when to add or remove
payloads. The driver already knows when it's disabling/enabling CRTCs, so
it also already knows when payloads should be added or removed.
Changes since v1:
* Refactor around all of the completely dead code changes that are
happening in amdgpu for some reason when they really shouldn't even be
there in the first place… :\
* Remove mention of sending one ACT per series of payload updates. As Wayne
Lin pointed out, there are apparently hubs on the market that don't work
correctly with this scheme and require a separate ACT per payload update.
* Fix accidental drop of mst_mgr.lock - Wayne Lin
* Remove mentions of allowing multiple ACT updates per payload change,
mention that this is a result of vendors not consistently supporting this
part of the spec and requiring a unique ACT for each payload change.
* Get rid of reference to drm_dp_mst_port in DC - turns out I just got
myself confused by DC and we don't actually need this.
Changes since v2:
* Get rid of fix for not sending payload deallocations if ddps=0 and just
go back to wayne's fix
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-18-lyude@redhat.com
Currently, we set drm_dp_atomic_payload->time_slots to 0 in order to
indicate that we're about to delete a payload in the current atomic state.
Since we're going to be dropping all of the legacy code for handling the
payload table however, we need to be able to ensure that we still keep
track of the current time slot allocations for each payload so we can reuse
this info when asking the root MST hub to delete payloads. We'll also be
using it to recalculate the start slots of each VC.
So, let's keep track of the intent of a payload in drm_dp_atomic_payload by
adding ->delete, which we set whenever we're planning on deleting a payload
during the current atomic commit.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-16-lyude@redhat.com
We want to start cutting down on all of the places that we use port
validation, so that ports may be removed from the topology as quickly as
possible to minimize the number of errors we run into as a result of being
out of sync with the current topology status. This isn't a very typical
scenario and I don't think I've ever even run into it - but since the next
commit is going to make some changes to payload updates depending on their
hotplug status I think it's a probably good idea to take precautions.
Let's do this with CSNs by moving some code around so that we only queue
link address probing work at the end of handling all CSNs - allowing us to
make sure we drop as many topology references as we can beforehand.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-15-lyude@redhat.com
There's another kind of situation where we could potentially race with
nonblocking modesets and MST, especially if we were to only use the locking
provided by atomic modesetting:
* Display 1 begins as enabled on DP-1 in SST mode
* Display 1 switches to MST mode, exposes one sink in MST mode
* Userspace does non-blocking modeset to disable the SST display
* Userspace does non-blocking modeset to enable the MST display with a
different CRTC, but the SST display hasn't been fully taken down yet
* Execution order between the last two commits isn't guaranteed since they
share no drm resources
We can fix this however, by ensuring that we always pull in the atomic
topology state whenever a connector capable of driving an MST display
performs its atomic check - and then tracking CRTC commits happening on the
SST connector in the MST topology state. So, let's add some simple helpers
for doing that and hook them up in various drivers.
v2:
* Use intel_dp_mst_source_support() to check for MST support in i915, fixes
CI failures
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-14-lyude@redhat.com
Currently with the MST helpers we avoid releasing payloads _and_ avoid
pulling in the MST state if there aren't any actual payload changes. While
we want to keep the first step, we need to now make sure that we're always
pulling in the MST state on all modesets that can modify payloads - even if
the resulting payloads in the atomic state are identical to the previous
ones.
This is mainly to make it so that if a CRTC is still assigned to a
connector but is set to DPMS off, the CRTC still holds it's payload
allocation in the atomic state and still appropriately pulls in the MST
state for commit tracking. Otherwise, we'll occasionally forget to update
MST payloads from changes caused by non-atomic DPMS changes. Doing this
also allows us to track bandwidth limitations in a state correctly even
between DPMS changes, so that there's no chance of a simple ->active change
being rejected by the atomic check.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-11-lyude@redhat.com
As Daniel Vetter pointed out, if we only use the atomic modesetting locks
with MST it's technically possible for a driver with non-blocking modesets
to race when it comes to MST displays - as we make the mistake of not doing
our own CRTC commit tracking in the topology_state object.
This could potentially cause problems if something like this happens:
* User starts non-blocking commit to disable CRTC-1 on MST topology 1
* User starts non-blocking commit to enable CRTC-2 on MST topology 1
There's no guarantee here that the commit for disabling CRTC-2 will only
occur after CRTC-1 has finished, since neither commit shares a CRTC - only
the private modesetting object for MST. Keep in mind this likely isn't a
problem for blocking modesets, only non-blocking.
So, begin fixing this by keeping track of which CRTCs on a topology have
changed by keeping track of which CRTCs we release or allocate timeslots
on. As well, add some helpers for:
* Setting up the drm_crtc_commit structs in the ->commit_setup hook
* Waiting for any CRTC dependencies from the previous topology state
v2:
* Use drm_dp_mst_atomic_setup_commit() directly - Jani
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-9-lyude@redhat.com
VCPI is only sort of the correct term here, originally the majority of this
code simply referred to timeslots vaguely as "slots" - and since I started
working on it and adding atomic functionality, the name "VCPI slots" has
been used to represent time slots.
Now that we actually have consistent access to the DisplayPort spec thanks
to VESA, I now know this isn't actually the proper term - as the
specification refers to these as time slots.
Since we're trying to make this code as easy to figure out as possible,
let's take this opportunity to correct this nomenclature and call them by
their proper name - timeslots. Likewise, we rename various functions
appropriately, along with replacing references in the kernel documentation
and various debugging messages.
It's important to note that this patch series leaves the legacy MST code
untouched for the most part, which is fine since we'll be removing it soon
anyhow. There should be no functional changes in this series.
v2:
* Add note that Wayne Lin from AMD suggested regarding slots being between
the source DP Tx and the immediate downstream DP Rx
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-5-lyude@redhat.com
Currently, there is no way to identify if DSC pass-through can be
enabled and what aux DSC pass-through requests ought to be sent to. So,
add a variable to struct drm_dp_mst_port that keeps track of the
aforementioned information.
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Drive-by cleanup, we don't need to validate the port references here as we
already previously went through the effort of refactoring things such that
we're guaranteed to be able to access ->mstb and ->port safely from
drm_dp_check_and_send_link_address(), since the only two places in the
codebase that drop an MST reference in such a way that it would remove it
from the topology are both protected under probe_lock.
Thanks for that, past Lyude!
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220602201757.30431-2-lyude@redhat.com
Pull drm updates from Dave Airlie:
"Intel have enabled DG2 on certain SKUs for laptops, AMD has started
some new GPU support, msm has user allocated VA controls
dma-buf:
- add dma_resv_replace_fences
- add dma_resv_get_singleton
- make dma_excl_fence private
core:
- EDID parser refactorings
- switch drivers to drm_mode_copy/duplicate
- DRM managed mutex initialization
display-helper:
- put HDMI, SCDC, HDCP, DSC and DP into new module
gem:
- rework fence handling
ttm:
- rework bulk move handling
- add common debugfs for resource managers
- convert to kvcalloc
format helpers:
- support monochrome formats
- RGB888, RGB565 to XRGB8888 conversions
fbdev:
- cfb/sys_imageblit fixes
- pagelist corruption fix
- create offb platform device
- deferred io improvements
sysfb:
- Kconfig rework
- support for VESA mode selection
bridge:
- conversions to devm_drm_of_get_bridge
- conversions to panel_bridge
- analogix_dp - autosuspend support
- it66121 - audio support
- tc358767 - DSI to DPI support
- icn6211 - PLL/I2C fixes, DT property
- adv7611 - enable DRM_BRIDGE_OP_HPD
- anx7625 - fill ELD if no monitor
- dw_hdmi - add audio support
- lontium LT9211 support, i.MXMP LDB
- it6505: Kconfig fix, DPCD set power fix
- adv7511 - CEC support for ADV7535
panel:
- ltk035c5444t, B133UAN01, NV3052C panel support
- DataImage FG040346DSSWBG04 support
- st7735r - DT bindings fix
- ssd130x - fixes
i915:
- DG2 laptop PCI-IDs ("motherboard down")
- Initial RPL-P PCI IDs
- compute engine ABI
- DG2 Tile4 support
- DG2 CCS clear color compression support
- DG2 render/media compression formats support
- ATS-M platform info
- RPL-S PCI IDs added
- Bump ADL-P DMC version to v2.16
- Support static DRRS
- Support multiple eDP/LVDS native mode refresh rates
- DP HDR support for HSW+
- Lots of display refactoring + fixes
- GuC hwconfig support and query
- sysfs support for multi-tile
- fdinfo per-client gpu utilisation
- add geometry subslices query
- fix prime mmap with LMEM
- fix vm open count and remove vma refcounts
- contiguous allocation fixes
- steered register write support
- small PCI BAR enablement
- GuC error capture support
- sunset igpu legacy mmap support for newer devices
- GuC version 70.1.1 support
amdgpu:
- Initial SoC21 support
- SMU 13.x enablement
- SMU 13.0.4 support
- ttm_eu cleanups
- USB-C, GPUVM updates
- TMZ fixes for RV
- RAS support for VCN
- PM sysfs code cleanup
- DC FP rework
- extend CG/PG flags to 64-bit
- SI dpm lockdep fix
- runtime PM fixes
amdkfd:
- RAS/SVM fixes
- TLB flush fixes
- CRIU GWS support
- ignore bogus MEC signals more efficiently
msm:
- Fourcc modifier for tiled but not compressed layouts
- Support for userspace allocated IOVA (GPU virtual address)
- DPU: DSC (Display Stream Compression) support
- DP: eDP support
- DP: conversion to use drm_bridge and drm_bridge_connector
- Merge DPU1 and MDP5 MDSS driver
- DPU: writeback support
nouveau:
- make some structures static
- make some variables static
- switch to drm_gem_plane_helper_prepare_fb
radeon:
- misc fixes/cleanups
mxsfb:
- rework crtc mode setting
- LCDIF CRC support
etnaviv:
- fencing improvements
- fix address space collisions
- cleanup MMU reference handling
gma500:
- GEM/GTT improvements
- connector handling fixes
komeda:
- switch to plane reset helper
mediatek:
- MIPI DSI improvements
omapdrm:
- GEM improvements
qxl:
- aarch64 support
vc4:
- add a CL submission tracepoint
- HDMI YUV support
- HDMI/clock improvements
- drop is_hdmi caching
virtio:
- remove restriction of non-zero blob types
vmwgfx:
- support for cursormob and cursorbypass 4
- fence improvements
tidss:
- reset DISPC on startup
solomon:
- SPI support
- DT improvements
sun4i:
- allwinner D1 support
- drop is_hdmi caching
imx:
- use swap() instead of open-coding
- use devm_platform_ioremap_resource
- remove redunant initializations
ast:
- Displayport support
rockchip:
- Refactor IOMMU initialisation
- make some structures static
- replace drm_detect_hdmi_monitor with drm_display_info.is_hdmi
- support swapped YUV formats,
- clock improvements
- rk3568 support
- VOP2 support
mediatek:
- MT8186 support
tegra:
- debugabillity improvements"
* tag 'drm-next-2022-05-25' of git://anongit.freedesktop.org/drm/drm: (1740 commits)
drm/i915/dsi: fix VBT send packet port selection for ICL+
drm/i915/uc: Fix undefined behavior due to shift overflowing the constant
drm/i915/reg: fix undefined behavior due to shift overflowing the constant
drm/i915/gt: Fix use of static in macro mismatch
drm/i915/audio: fix audio code enable/disable pipe logging
drm/i915: Fix CFI violation with show_dynamic_id()
drm/i915: Fix 'mixing different enum types' warnings in intel_display_power.c
drm/i915/gt: Fix build error without CONFIG_PM
drm/msm/dpu: handle pm_runtime_get_sync() errors in bind path
drm/msm/dpu: add DRM_MODE_ROTATE_180 back to supported rotations
drm/msm: don't free the IRQ if it was not requested
drm/msm/dpu: limit writeback modes according to max_linewidth
drm/amd: Don't reset dGPUs if the system is going to s2idle
drm/amdgpu: Unmap legacy queue when MES is enabled
drm: msm: fix possible memory leak in mdp5_crtc_cursor_set()
drm/msm: Fix fb plane offset calculation
drm/msm/a6xx: Fix refcount leak in a6xx_gpu_init
drm/msm/dsi: don't powerup at modeset time for parade-ps8640
drm/rockchip: Change register space names in vop2
dt-bindings: display: rockchip: make reg-names mandatory for VOP2
...
[Why]
It's reasonable that we receive NAK while doing DP_REMOTE_DPCD_READ.
Downstream device might reply NAK with the reason and source should
react accordingly.
e.g.
1. When downstream device can't handle corresponding message in time,
it then replies NAK as reason been set as DEFER.
2. When multi-function branch-sink device doesn't enumerate virtual
DP peer devices for those multi-function down facing ports. Without
virtual DPCD, branch device might reply NAK with reason as BAD_PARAM
indicating this port can't do aux DPCD read.
It's expected result. Not an error.
[How]
Use drm_dbg_kms() to replace drm_err() when receive NAK.
Changes since v1:
* drm_dp_mst_topology.c file path changed. Folder was rename from
'dp' to 'display'
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[fixed some indenting issues]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220428124944.1683680-1-Wayne.Lin@amd.com
Rename dp/ to display/ to account for additional display-related
helpers, such as HDMI. Update all related include statements. No
functional changes.
Various drivers, such as i915 and amdgpu, use similar naming scheme
by putting code for video-output standards into a local display/
directory. The new directory's name is aligned with this convention.
v2:
* update commit message (Javier)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-3-tzimmermann@suse.de
