drm/i915: Disable hotplug detection works during driver init/shutdown

As described in the previous patch, an unexpected connector
detection/modeset started from the intel_hotplug::hotplug_work can
happen during the driver init/shutdown sequence. Prevent these by
disabling the queuing of and flushing all the intel_hotplug work that
can start them at the beginning of the init/shutdown sequence and allow
the queuing only while the display is in the initialized state.

Other work items - like the intel_connector::modeset_retry_work or the
MST probe works - are still enabled and can start a detection/modeset,
but after the previous patch these will be rejected. Disabling these
works as well is for a follow-up patchset.

Link: https://patchwork.freedesktop.org/patch/msgid/20240104083008.2715733-9-imre.deak@intel.com
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>

drm/i915/hotplug: refactor hotplug init slightly

Rename intel_hpd_init_work() to the more generic intel_hpd_init_early(),
and move the hotplug storm initialization there. This lets us move the
HPD_STORM_DEFAULT_THRESHOLD macro to intel_hotplug.c too.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220916130634.3781122-2-jani.nikula@intel.com

drm/i915/hotplug: move hotplug storm debugfs to intel_hotplug.c

The debugfs should be where the implementation details are.

v2: Rebase

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220916130634.3781122-1-jani.nikula@intel.com

drm/i915: Reorder hpd init vs. display resume

Currently we call .hpd_irq_setup() directly just before display
resume, and follow it with another call via intel_hpd_init()
just afterwards. Assuming the hpd pins are marked as enabled
during the open-coded call these two things do exactly the
same thing (ie. enable HPD interrupts). Which even makes sense
since we definitely need working HPD interrupts for MST sideband
during the display resume.

So let's nuke the open-coded call and move the intel_hpd_init()
call earlier. However we need to leave the poll_init_work stuff
behind after the display resume as that will trigger display
detection while we're resuming. We don't want that trampling over
the display resume process. To make this a bit more symmetric
we turn this into a intel_hpd_poll_{enable,disable}() pair.
So we end up with the following transformation:
intel_hpd_poll_init() -> intel_hpd_poll_enable()
lone intel_hpd_init() -> intel_hpd_init()+intel_hpd_poll_disable()
.hpd_irq_setup()+resume+intel_hpd_init() -> intel_hpd_init()+resume+intel_hpd_poll_disable()

If we really would like to prevent all *long* HPD processing during
display resume we'd need some kind of software mechanism to simply
ignore all long HPDs. Currently we appear to have that just for
fbdev via ifbdev->hpd_suspended. Since we aren't exploding left and
right all the time I guess that's mostly sufficient.

For a bit of history on this, we first got a mechanism to block
hotplug processing during suspend in commit 15239099d7a7 ("drm/i915:
enable irqs earlier when resuming") on account of moving the irq enable
earlier. This then got removed in commit 50c3dc970a09 ("drm/fb-helper:
Fix hpd vs. initial config races") because the fdev initial config
got pushed to a later point. The second ad-hoc hpd_irq_setup() for
resume was added in commit 0e32b39ceed6 ("drm/i915: add DP 1.2 MST
support (v0.7)") to be able to do MST sideband during the resume.
And finally we got a partial resurrection of the hpd blocking
mechanism in commit e8a8fedd57fd ("drm/i915: Block fbdev HPD
processing during suspend"), but this time it only prevent fbdev
from handling hpd while resuming.

v2: Leave the poll_init_work behind
v3: Remove the extra intel_hpd_poll_disable() from display reset (Lyude)
Add the missing intel_hpd_poll_disable() to display init (Imre)

Cc: Lyude Paul <lyude@redhat.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201013181137.30560-1-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

drm/i915/dp_mst: Work around out-of-spec adapters filtering short pulses

Some TypeC -> native DP adapters, at least the Club 3D CAC-1557 adapter,
incorrectly filter out HPD short pulses with a duration less than
~540 usec, leading to MST probe failures.

According to the DP Standard 2.0 section 5.1.4:
- DP sinks should generate short pulses in the 500 usec -> 1 msec range
- DP sources should detect short pulses in the 250 usec -> 2 msec range

According to the DP Alt Mode on TypeC Standard section 3.9.2, adapters
should detect and forward short pulses according to how sources should
detect them as specified in the DP Standard (250 usec -> 2 msec).

Based on the above filtering out short pulses with a duration less than
540 usec is incorrect.

To make such adapters work add support for a driver polling on MST
inerrupt flags, and wire this up in the i915 driver. The sink can clear
an interrupt it raised after 110 msec if the source doesn't respond, so
use a 50 msec poll period to avoid missing an interrupt. Polling of the
MST interrupt flags is explicitly allowed by the DP Standard.

This fixes MST probe failures I saw using this adapter and a DELL U2515H
monitor.

v2:
- Fix the wait event timeout for the no-poll case.
v3 (Ville):
- Fix the short pulse duration limits in the commit log prescribed by the
DP Standard.
- Add code comment explaining why/how polling is used.
- Factor out a helper to schedule the port's hpd irq handler and move it
to the rest of hotplug handlers.
- Document the new MST callback.
- s/update_hpd_irq_state/poll_hpd_irq/

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200604184500.23730-2-imre.deak@intel.com

drm/i915: Add a retry counter for hotplug detect retries

On TypeC connectors we need to retry the detection after hotplug events
for a longer time, so add a retry counter to support this. The next
patch will add detection retries on TypeC ports needing this.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200330095425.29113-1-imre.deak@intel.com

drm/i915: significantly reduce the use of <drm/i915_drm.h>

The #include has been splattered all over the place, but there are
precious few places, all .c files, that actually need it.

v2: remove leftover double newlines

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200225133131.3301-1-jani.nikula@intel.com

drm: Move port definition back to i915 header

We dont need the definition of the enum port outside I915, anymore.
Hence move enum port definition into I915 driver itself.

v2:
intel_display.h is included in intel_hdcp.h
v3:
enum port is declared in headers.
v4:
commit msg is rephrased.
v5:
copyright year is updated [Tomas]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Shashank Sharma <shashank.sharma@intel.com>
Reviewed-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190828164216.405-3-ramalingam.c@intel.com

drm/i915: Add support for retrying hotplug

There is some scenarios that we are aware that sink probe can fail,
so lets add the infrastructure to let hotplug() hook to request
another probe after some time.

v2: Handle shared HPD pins (Imre)
v3: Rebased
v4: Renamed INTEL_HOTPLUG_NOCHANGE to INTEL_HOTPLUG_UNCHANGED to keep
it consistent(Rodrigo)
v5: Making the working queue used explicit through all the callers to
hotplug_work (Ville)

Tested-by: Timo Aaltonen <tjaalton@ubuntu.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190712005343.24571-1-jose.souza@intel.com

drm/i915: move modesetting core code under display/

Now that we have a new subdirectory for display code, continue by moving
modesetting core code.

display/intel_frontbuffer.h sticks out like a sore thumb, otherwise this
is, again, a surprisingly clean operation.

v2:
- don't move intel_sideband.[ch] (Ville)
- use tabs for Makefile file lists and sort them

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613084416.6794-3-jani.nikula@intel.com