Commit Graph

17 Commits

Author SHA1 Message Date
Lyude Paul
6366fc70de drm/display/dp_mst: Maintain time slot allocations when deleting payloads
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
2022-08-23 16:53:42 -04:00
Lyude Paul
a76eb4297f drm/display/dp_mst: Add helpers for serializing SST <-> MST transitions
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
2022-08-23 16:53:41 -04:00
Lyude Paul
a5c2c0d164 drm/display/dp_mst: Add nonblocking helpers for DP MST
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
2022-08-23 16:53:37 -04:00
Lyude Paul
0bee2ae29e drm/display/dp_mst: Add some missing kdocs for atomic MST structs
Since we're about to start adding some stuff here, we may as well fill in
any missing documentation that we forgot to write.

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/20220817193847.557945-7-lyude@redhat.com
2022-08-23 16:53:36 -04:00
Lyude Paul
df78f7f660 drm/display/dp_mst: Call them time slots, not VCPI slots
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
2022-08-23 16:53:35 -04:00
Lyude Paul
48b6b3726f drm/display/dp_mst: Rename drm_dp_mst_vcpi_allocation
In retrospect, the name I chose for this originally is confusing, as
there's a lot more info in here then just the VCPI. This really should be
called a payload. Let's make it more obvious that this is meant to be
related to the atomic state and is about payloads by renaming it to
drm_dp_mst_atomic_payload. Also, rename various variables throughout the
code that use atomic payloads.

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/20220817193847.557945-4-lyude@redhat.com
2022-08-23 16:53:34 -04:00
Douglas Anderson
841d742f09 drm/dp: Add wait_hpd_asserted() callback to struct drm_dp_aux
Sometimes it's useful for users of the DP AUX bus (like panels) to be
able to poll HPD. Let's add a callback that allows DP AUX busses
drivers to provide this.

Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220614145327.v4.1.Icf57bb12233a47727013c6ab69eebf803e22ebc1@changeid
2022-06-21 09:03:49 -07:00
Douglas Anderson
7d188c521d drm: Fix htmldocs indentation warning w/ DP AUX power requirements
Two blank lines are needed to make the rst valid.

Fixes: 69ef4a192b ("drm: Document the power requirements for DP AUX transfers")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220611095445.1.I534072d346b1ebbf0db565b714de9b65cbb24651@changeid
2022-06-11 14:53:30 -07:00
Douglas Anderson
3800b17109 drm/dp: Add callbacks to make using DP AUX bus properly easier
As talked about in this patch in the kerneldoc of
of_dp_aux_populate_ep_device() and also in the past in commit
a1e3667a98 ("drm/bridge: ti-sn65dsi86: Promote the AUX channel to
its own sub-dev"), it can be difficult for eDP controller drivers to
know when the panel has finished probing when they're using
of_dp_aux_populate_ep_devices().

The ti-sn65dsi86 driver managed to solve this because it was already
broken up into a bunch of sub-drivers. That means we could solve the
problem there by adding a new sub-driver to get the panel. We could
use the traditional -EPROBE_DEFER retry mechansim to handle the case
where the panel hadn't probed yet.

In parade-ps8640 we didn't really solve this. The code just expects
the panel to be ready right away. While reviewing the code originally
I had managed to convince myself it was fine to just expect the panel
right away, but additional testing has shown that not to be the
case. We could fix parade-ps8640 like we did ti-sn65dsi86 but it's
pretty cumbersome (since we're not already broken into multiple
drivers) and requires a bunch of boilerplate code.

After discussion [1] it seems like the best solution for most people
is:
- Accept that there's always at most one device that will probe as a
  result of the DP AUX bus (it may have sub-devices, but there will be
  one device _directly_ probed).
- When that device finishes probing, we can just have a call back.

This patch implements that idea. We'll now take a callback as an
argument to the populate function. To make this easier to land in
pieces, we'll make wrappers for the old functions. The functions with
the new name (which make it clear that we only have one child) will
take the callback and the functions with the old name will temporarily
wrap.

[1] https://lore.kernel.org/r/CAD=FV=Ur3afHhsXe7a3baWEnD=MFKFeKRbhFU+bt3P67G0MVzQ@mail.gmail.com

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220510122726.v3.2.I4182ae27e00792842cb86f1433990a0ef9c0a073@changeid
2022-06-02 15:14:16 -07:00
Douglas Anderson
69ef4a192b drm: Document the power requirements for DP AUX transfers
When doing DP AUX transfers there are two actors that need to be
powered in order for the DP AUX transfer to work: the DP source and
the DP sink. Commit bacbab58f0 ("drm: Mention the power state
requirement on side-channel operations") added some documentation
saying that the DP source is required to power itself up (if needed)
to do AUX transfers. However, that commit doesn't talk anything about
the DP sink.

For full fledged DP the sink isn't really a problem. It's expected
that if an external DP monitor isn't plugged in that attempting to do
AUX transfers won't work. It's also expected that if a DP monitor is
plugged in (and thus asserting HPD) then AUX transfers will work.

When we're looking at eDP, however, things are less obvious. Let's add
some documentation about expectations. Here's what we'll say:

1. We don't expect the DP AUX transfer function to power on an eDP
panel. If an eDP panel is physically connected but powered off then it
makes sense for the transfer to fail.

2. We'll document that the official way to power on a panel is via the
bridge chain, specifically by making sure that the panel's prepare
function has been called (which is called by
panel_bridge_pre_enable()). It's already specified in the kernel doc
of drm_panel_prepare() that this is the way to power the panel on and
also that after this call "it is possible to communicate with any
integrated circuitry via a command bus."

3. We'll also document that for code running in the panel driver
itself that it is legal for the panel driver to power itself up
however it wants (it doesn't need to officially call
drm_panel_pre_enable()) and then it can do AUX bus transfers. This is
currently the way that edp-panel works when it's running atop the DP
AUX bus.

NOTE: there was much discussion of all of this in response to v1 [1]
of this patch. A summary of that is:
* With the Intel i195 driver, apparently eDP panels do get powered
  up. We won't forbid this but it is expected that code that wants to
  run on a variety of platforms should ensure that the drm_panel's
  prepare() function has been called.
* There is at least a reasonable amount of agreement that the
  transfer() functions itself shouldn't be responsible for powering
  the panel. It's proposed that if we need the DP AUX dev nodes to be
  robust for eDP that the code handling the DP AUX dev nodes could
  handle powering the panel by ensuring that the panel's prepare()
  call was made. Potentially drm_dp_aux_dev_get_by_minor() could be a
  good place to do this. This is left as a future exercise. Until
  that's fixed the DP AUX dev nodes for eDP are probably best just
  used for debugging.
* If a panel could be in PSR and DP AUX via the dev node needs to be
  reliable then we need to be able to pull the panel out of PSR. On
  i915 this is also apparently handled as part of the transfer()
  function.

[1] https://lore.kernel.org/r/20220503162033.1.Ia8651894026707e4fa61267da944ff739610d180@changeid

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220509161733.v2.1.Ia8651894026707e4fa61267da944ff739610d180@changeid
2022-05-19 17:22:27 -07:00
Dave Airlie
15e2b419a8 drm-misc-next for 5.19:
UAPI Changes:
 
 Cross-subsystem Changes:
 
 Core Changes:
   - Introduction of display-helper module, and rework of the DP, DSC,
     HDCP, HDMI and SCDC headers
   - doc: Improvements for tiny drivers, link to external resources
   - formats: helper to convert from RGB888 and RGB565 to XRGB8888
   - modes: make width-mm/height-mm check mandatory in of_get_drm_panel_display_mode
   - ttm: Convert from kvmalloc_array to kvcalloc
 
 Driver Changes:
   - bridge:
     - analogix_dp: Fix error handling in probe
     - dw_hdmi: Coccinelle fixes
     - it6505: Fix Kconfig dependency on DRM_DP_AUX_BUS
   - panel:
     - new panel: DataImage FG040346DSSWBG04
   - amdgpu: ttm_eu cleanups
   - mxsfb: Rework CRTC mode setting
   - nouveau: Make some variables static
   - sun4i: Drop drm_display_info.is_hdmi caching, support for the
     Allwinner D1
   - vc4: Drop drm_display_info.is_hdmi caching
   - vmwgfx: Fence improvements
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Merge tag 'drm-misc-next-2022-04-28' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 5.19:

UAPI Changes:

Cross-subsystem Changes:

Core Changes:
  - Introduction of display-helper module, and rework of the DP, DSC,
    HDCP, HDMI and SCDC headers
  - doc: Improvements for tiny drivers, link to external resources
  - formats: helper to convert from RGB888 and RGB565 to XRGB8888
  - modes: make width-mm/height-mm check mandatory in of_get_drm_panel_display_mode
  - ttm: Convert from kvmalloc_array to kvcalloc

Driver Changes:
  - bridge:
    - analogix_dp: Fix error handling in probe
    - dw_hdmi: Coccinelle fixes
    - it6505: Fix Kconfig dependency on DRM_DP_AUX_BUS
  - panel:
    - new panel: DataImage FG040346DSSWBG04
  - amdgpu: ttm_eu cleanups
  - mxsfb: Rework CRTC mode setting
  - nouveau: Make some variables static
  - sun4i: Drop drm_display_info.is_hdmi caching, support for the
    Allwinner D1
  - vc4: Drop drm_display_info.is_hdmi caching
  - vmwgfx: Fence improvements

Signed-off-by: Dave Airlie <airlied@redhat.com>

# gpg: Signature made Thu 28 Apr 2022 17:52:13 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/20220428075237.yypztjha7hetphcd@houat
2022-04-29 11:33:00 +10:00
Thomas Zimmermann
644edf52b6 drm/display: Move SCDC helpers into display-helper library
SCDC is the Status and Control Data Channel for HDMI. Move the SCDC
helpers into display/ and split the header into files for core and
helpers. Update all affected drivers. No functional changes.

To avoid the proliferation of Kconfig options, SCDC is part of DRM's
support for HDMI. If necessary, a new option could make SCDC an
independent feature.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-9-tzimmermann@suse.de
2022-04-25 11:19:37 +02:00
Thomas Zimmermann
4fc8cb47fc drm/display: Move HDMI helpers into display-helper module
Move DRM's HMDI helpers into the display/ subdirectoy and add it
to DRM's display helpers. Update all affected drivers. No functional
changes.

The HDMI helpers were implemented in the EDID and connector code, but
are actually unrelated. With the move to the display-helper library, we
can remove the dependency on drm_edid.{c,h} in some driver's HDMI source
files.

Several of the HDMI helpers remain in EDID code because both share parts
of their implementation internally. With better refractoring of the EDID
code, those HDMI helpers could be moved into the display-helper library
as well.

v3:
	* fix Kconfig dependencies (Javier)
v2:
	* reduce HDMI helpers to avoid exporting functions (Jani)
	* fix include statements (Jani, Javier)
	* update Kconfig symbols

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-8-tzimmermann@suse.de
2022-04-25 11:19:36 +02:00
Thomas Zimmermann
6a99099fe1 drm/display: Move HDCP helpers into display-helper module
Move DRM's HDCP helper library into the display/ subdirectory and add
it to DRM's display helpers. Split the header file into core and helpers.
Update all affected drivers. No functional changes.

v3:
	* fix Kconfig dependencies
v2:
	* fix include statements (Jani, Javier)
	* update Kconfig symbols

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-7-tzimmermann@suse.de
2022-04-25 11:19:36 +02:00
Thomas Zimmermann
2a64b14735 drm/display: Move DSC header and helpers into display-helper module
DSC is the Display Stream Compression standard for DisplayPort. Move
the DSC code into display/ and split the header into files for protocol
core and DRM helpers. Adapt all users of the code. No functional
changes.

To avoid the proliferation of Kconfig options, DSC is part of DRM's
support for DisplayPort. If necessary, a new option could make DSC an
independent feature.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-6-tzimmermann@suse.de
2022-04-25 11:19:36 +02:00
Thomas Zimmermann
5d1b8b4a14 drm/display: Split DisplayPort header into core and helper
Move DisplayPort protocol constants and structures into the new
header drm_dp.h, which can be used by DRM core components. The
existing header drm_dp_helper.h now only contains helper code for
graphics drivers. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220421073108.19226-5-tzimmermann@suse.de
2022-04-25 11:19:36 +02:00
Thomas Zimmermann
da68386d9e drm: Rename dp/ to display/
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
2022-04-25 11:17:45 +02:00