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  1. 09 3月, 2019 1 次提交
  3. 05 3月, 2019 1 次提交
  5. 27 2月, 2019 4 次提交
  7. 21 2月, 2019 7 次提交
  9. 16 2月, 2019 1 次提交
  11. 13 2月, 2019 2 次提交
  13. 12 2月, 2019 1 次提交
    • L
      drm/i915: Block fbdev HPD processing during suspend · e8a8fedd
      由 Lyude Paul 提交于 
      When resuming, we check whether or not any previously connected
MST topologies are still present and if so, attempt to resume them. If
this fails, we disable said MST topologies and fire off a hotplug event
so that userspace knows to reprobe.

However, sending a hotplug event involves calling
drm_fb_helper_hotplug_event(), which in turn results in fbcon doing a
connector reprobe in the caller's thread - something we can't do at the
point in which i915 calls drm_dp_mst_topology_mgr_resume() since
hotplugging hasn't been fully initialized yet.

This currently causes some rather subtle but fatal issues. For example,
on my T480s the laptop dock connected to it usually disappears during a
suspend cycle, and comes back up a short while after the system has been
resumed. This guarantees pretty much every suspend and resume cycle,
drm_dp_mst_topology_mgr_set_mst(mgr, false); will be caused and in turn,
a connector hotplug will occur. Now it's Rute Goldberg time: when the
connector hotplug occurs, i915 reprobes /all/ of the connectors,
including eDP. However, eDP probing requires that we power on the panel
VDD which in turn, grabs a wakeref to the appropriate power domain on
the GPU (on my T480s, this is the PORT_DDI_A_IO domain). This is where
things start breaking, since this all happens before
intel_power_domains_enable() is called we end up leaking the wakeref
that was acquired and never releasing it later. Come next suspend/resume
cycle, this causes us to fail to shut down the GPU properly, which
causes it not to resume properly and die a horrible complicated death.

(as a note: this only happens when there's both an eDP panel and MST
topology connected which is removed mid-suspend. One or the other seems
to always be OK).

We could try to fix the VDD wakeref leak, but this doesn't seem like
it's worth it at all since we aren't able to handle hotplug detection
while resuming anyway. So, let's go with a more robust solution inspired
by nouveau: block fbdev from handling hotplug events until we resume
fbdev. This allows us to still send sysfs hotplug events to be handled
later by user space while we're resuming, while also preventing us from
actually processing any hotplug events we receive until it's safe.

This fixes the wakeref leak observed on the T480s and as such, also
fixes suspend/resume with MST topologies connected on this machine.

Changes since v2:
* Don't call drm_fb_helper_hotplug_event() under lock, do it after lock
  (Chris Wilson)
* Don't call drm_fb_helper_hotplug_event() in
  intel_fbdev_output_poll_changed() under lock (Chris Wilson)
* Always set ifbdev->hpd_waiting (Chris Wilson)
Signed-off-by: NLyude Paul <lyude@redhat.com>
Fixes: 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)")
Cc: Todd Previte <tprevite@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v3.17+
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129191001.442-2-lyude@redhat.com
(cherry picked from commit fe5ec656)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
      e8a8fedd
  15. 09 2月, 2019 1 次提交
    • C
      drm/i915: Revoke mmaps and prevent access to fence registers across reset · 2caffbf1
      由 Chris Wilson 提交于 
      Previously, we were able to rely on the recursive properties of
struct_mutex to allow us to serialise revoking mmaps and reacquiring the
FENCE registers with them being clobbered over a global device reset.
I then proceeded to throw out the baby with the bath water in order to
pursue a struct_mutex-less reset.

Perusing LWN for alternative strategies, the dilemma on how to serialise
access to a global resource on one side was answered by
https://lwn.net/Articles/202847/ -- Sleepable RCU:

    1  int readside(void) {
    2      int idx;
    3      rcu_read_lock();
    4	   if (nomoresrcu) {
    5          rcu_read_unlock();
    6	       return -EINVAL;
    7      }
    8	   idx = srcu_read_lock(&ss);
    9	   rcu_read_unlock();
    10	   /* SRCU read-side critical section. */
    11	   srcu_read_unlock(&ss, idx);
    12	   return 0;
    13 }
    14
    15 void cleanup(void)
    16 {
    17     nomoresrcu = 1;
    18     synchronize_rcu();
    19     synchronize_srcu(&ss);
    20     cleanup_srcu_struct(&ss);
    21 }

No more worrying about stop_machine, just an uber-complex mutex,
optimised for reads, with the overhead pushed to the rare reset path.

However, we do run the risk of a deadlock as we allocate underneath the
SRCU read lock, and the allocation may require a GPU reset, causing a
dependency cycle via the in-flight requests. We resolve that by declaring
the driver wedged and cancelling all in-flight rendering.

v2: Use expedited rcu barriers to match our earlier timing
characteristics.
v3: Try to annotate locking contexts for sparse
v4: Reduce selftest lock duration to avoid a reset deadlock with fences
v5: s/srcu/reset_backoff_srcu/
v6: Remove more stale comments

Testcase: igt/gem_mmap_gtt/hang
Fixes: eb8d0f5a ("drm/i915: Remove GPU reset dependence on struct_mutex")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190208153708.20023-2-chris@chris-wilson.co.uk
      2caffbf1
  17. 08 2月, 2019 7 次提交
  19. 07 2月, 2019 1 次提交
    • L
      drm/i915: Block fbdev HPD processing during suspend · fe5ec656
      由 Lyude Paul 提交于 
      When resuming, we check whether or not any previously connected
MST topologies are still present and if so, attempt to resume them. If
this fails, we disable said MST topologies and fire off a hotplug event
so that userspace knows to reprobe.

However, sending a hotplug event involves calling
drm_fb_helper_hotplug_event(), which in turn results in fbcon doing a
connector reprobe in the caller's thread - something we can't do at the
point in which i915 calls drm_dp_mst_topology_mgr_resume() since
hotplugging hasn't been fully initialized yet.

This currently causes some rather subtle but fatal issues. For example,
on my T480s the laptop dock connected to it usually disappears during a
suspend cycle, and comes back up a short while after the system has been
resumed. This guarantees pretty much every suspend and resume cycle,
drm_dp_mst_topology_mgr_set_mst(mgr, false); will be caused and in turn,
a connector hotplug will occur. Now it's Rute Goldberg time: when the
connector hotplug occurs, i915 reprobes /all/ of the connectors,
including eDP. However, eDP probing requires that we power on the panel
VDD which in turn, grabs a wakeref to the appropriate power domain on
the GPU (on my T480s, this is the PORT_DDI_A_IO domain). This is where
things start breaking, since this all happens before
intel_power_domains_enable() is called we end up leaking the wakeref
that was acquired and never releasing it later. Come next suspend/resume
cycle, this causes us to fail to shut down the GPU properly, which
causes it not to resume properly and die a horrible complicated death.

(as a note: this only happens when there's both an eDP panel and MST
topology connected which is removed mid-suspend. One or the other seems
to always be OK).

We could try to fix the VDD wakeref leak, but this doesn't seem like
it's worth it at all since we aren't able to handle hotplug detection
while resuming anyway. So, let's go with a more robust solution inspired
by nouveau: block fbdev from handling hotplug events until we resume
fbdev. This allows us to still send sysfs hotplug events to be handled
later by user space while we're resuming, while also preventing us from
actually processing any hotplug events we receive until it's safe.

This fixes the wakeref leak observed on the T480s and as such, also
fixes suspend/resume with MST topologies connected on this machine.

Changes since v2:
* Don't call drm_fb_helper_hotplug_event() under lock, do it after lock
  (Chris Wilson)
* Don't call drm_fb_helper_hotplug_event() in
  intel_fbdev_output_poll_changed() under lock (Chris Wilson)
* Always set ifbdev->hpd_waiting (Chris Wilson)
Signed-off-by: NLyude Paul <lyude@redhat.com>
Fixes: 0e32b39c ("drm/i915: add DP 1.2 MST support (v0.7)")
Cc: Todd Previte <tprevite@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v3.17+
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129191001.442-2-lyude@redhat.com
      fe5ec656
  21. 28 1月, 2019 1 次提交
  23. 24 1月, 2019 2 次提交
  25. 21 1月, 2019 1 次提交
  27. 16 1月, 2019 2 次提交
    • L
      drm/i915: Pass down rc in intel_encoder->compute_config() · 204474a6
      由 Lyude Paul 提交于 
      Something that I completely missed when implementing the new MST VCPI
atomic helpers is that with those helpers, there's technically a chance
of us having to grab additional modeset locks in ->compute_config() and
furthermore, that means we have the potential to hit a normal modeset
deadlock. However, because ->compute_config() only returns a bool this
means we can't return -EDEADLK when we need to drop locks and try again
which means we end up just failing the atomic check permanently. Whoops.

So, fix this by modifying ->compute_config() to pass down an actual
error code instead of a bool so that the atomic check can be restarted
on modeset deadlocks.

Thanks to Ville Syrjälä for pointing this out!

Changes since v1:
* Add some newlines
* Return only -EINVAL from hsw_crt_compute_config()
* Propogate return code from intel_dp_compute_dsc_params()
* Change all of the intel_dp_compute_link_config*() variants
* Don't miss if (hdmi_port_clock_valid()) branch in
  intel_hdmi_compute_config()

[Cherry-picked from drm-misc-next to drm-intel-next-queued to fix
 linux-next & drm-tip conflict, while waiting for proper propagation of
 the DP MST series that this commit fixes. In hindsight, a topic branch
 might have been a better approach for it.]
Signed-off-by: NLyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: eceae147 ("drm/dp_mst: Start tracking per-port VCPI allocations")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109320Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190115200800.3121-1-lyude@redhat.com
(cherry picked from commit 96550555)
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Acked-by: NDaniel Vetter <daniel@ffwll.ch>
      204474a6
    • L
      drm/i915: Pass down rc in intel_encoder->compute_config() · 96550555
      由 Lyude Paul 提交于 
      Something that I completely missed when implementing the new MST VCPI
atomic helpers is that with those helpers, there's technically a chance
of us having to grab additional modeset locks in ->compute_config() and
furthermore, that means we have the potential to hit a normal modeset
deadlock. However, because ->compute_config() only returns a bool this
means we can't return -EDEADLK when we need to drop locks and try again
which means we end up just failing the atomic check permanently. Whoops.

So, fix this by modifying ->compute_config() to pass down an actual
error code instead of a bool so that the atomic check can be restarted
on modeset deadlocks.

Thanks to Ville Syrjälä for pointing this out!

Changes since v1:
* Add some newlines
* Return only -EINVAL from hsw_crt_compute_config()
* Propogate return code from intel_dp_compute_dsc_params()
* Change all of the intel_dp_compute_link_config*() variants
* Don't miss if (hdmi_port_clock_valid()) branch in
  intel_hdmi_compute_config()
Signed-off-by: NLyude Paul <lyude@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: eceae147 ("drm/dp_mst: Start tracking per-port VCPI allocations")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109320Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190115200800.3121-1-lyude@redhat.com
      96550555
  29. 15 1月, 2019 4 次提交
  31. 11 1月, 2019 1 次提交
  33. 25 12月, 2018 1 次提交
  35. 18 12月, 2018 1 次提交
    • I
      drm/i915/icl: Fix HPD handling for TypeC legacy ports · f6bff60e
      由 Imre Deak 提交于 
      Atm HPD disconnect events on TypeC ports will break things, since we'll
switch the TypeC mode (between legacy and disconnected modes as well as
among USB DP alternate, Thunderbolt alternate and disconnected modes) on
the fly from the HPD disconnect interrupt work while the port may be
still active.

Even if the port happens to be not active during the disconnect we'd
still have a problem during a subsequent modeset or AUX transfer that
could happen regardless of the port's connected state. For instance the
system resume display mode restore code and userspace could perform a
modeset on the port or userspace could start an AUX transfer even if the
port is in disconnected state.

To fix this keep TypeC legacy ports in legacy mode whenever we're not
suspended. This mode is a static configuration as opposed to the
Thunderbolt and USB DP alternate modes between which we can switch
dynamically.

We determine if a TypeC port is legacy (wired to a legacy HDMI or a
legacy DP connector) via the VBT DDI port specific USB-TypeC and
Thunderbolt flags. If both these flags are cleared then the port is
configured for legacy mode.

On such legacy ports we'll run the TypeC PHY connect sequence explicitly
during driver loading and system resume (vs. running the sequence during
HPD processing). The connect will succeed even if the display is not
connected to begin with (or disappears during the suspended state) since
for legacy ports the PORT_TX_DFLEXDPPMS / DP_PHY_MODE_STATUS_COMPLETED
flag is always set (as opposed to the USB DP alternate mode where it
gets set only when a display is connected).

Correspondingly run the TypeC PHY disconnect sequence during system
suspend and driver unloading. For the unloading case I had to split
up intel_dp_encoder_destroy() to be able to have the 1. flush any
pending encoder work, 2. disconnect TC PHY, 3. call DRM core cleanup and
kfree on the encoder object.

For now run the PHY disconnect during suspend only for TypeC legacy
ports. We will need to disconnect even in USB DP alternate mode in the
future, but atm we don't have a way to reconnect the port in this mode
during resume if the display disappears while being suspended. So for
now punt on this case.

Note that we do not disconnect the port during runtime suspend; in
legacy mode there are no shared HW resources (PHY lanes) with other HW
blocks (USB), so no need to release / reacquire these resources as with
USB DP alternate mode. The only reason to disconnect legacy ports during
system suspend is that the PORT_TX_DFLEXDPPMS /
DP_PHY_MODE_STATUS_COMPLETED flag must be rechecked and the port must be
connected again during system resume. We'll also have to turn the check
for this flag into a poll, after figuring out what's the proper timeout
value for it.

v2:
- Remove the redundant special casing of legacy mode when doing a
  disconnect in icl_tc_port_connected(). It's guaranteed already that we
  won't disconnect legacy ports in that function.
- Add a note about the new intel_ddi_encoder_destroy() hook.
- Reword the commit message after switching to the VBT based detection.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108070
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108924
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181214182703.18865-4-imre.deak@intel.com
      f6bff60e
  37. 17 12月, 2018 1 次提交
    • M
      drm/i915/dsc: Add Per connector debugfs node for DSC support/enable · e845f099
      由 Manasi Navare 提交于 
      DSC can be supported per DP connector. This patch adds a per connector
debugfs node to expose DSC support capability by the kernel.
The same node can be used from userspace to force DSC enable.

force_dsc_en written through this debugfs node is used to force
DSC even for lower resolutions.

Credits to Ville Syrjala for suggesting the proper locks to be used
and to Lyude Paul for explaining how to use them in this context

v8:
* Add else if (ret) for drm_modeset_lock (Lyude)
v7:
* Get crtc, crtc_state from connector atomic state
and add proper locks and backoff (Ville, Chris Wilson, Lyude)
(Suggested-by: Ville Syrjala <ville.syrjala@linux.intel.com>)
* Use %zu for printing size_t variable (Lyude)
v6:
* Read fec_capable only for non edp (Manasi)
v5:
* Name it dsc sink support and also add
fec support in the same node (Ville)
v4:
* Add missed connector_status check (Manasi)
* Create i915_dsc_support node only for Gen >=10 (manasi)
* Access intel_dp->dsc_dpcd only if its not NULL (Manasi)
v3:
* Combine Force_dsc_en with this patch (Ville)
v2:
* Use kstrtobool_from_user to avoid explicit error checking (Lyude)
* Rebase on drm-tip (Manasi)

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Lyude Paul <lyude@redhat.com>
Signed-off-by: NManasi Navare <manasi.d.navare@intel.com>
Reviewed-by: NLyude Paul <lyude@redhat.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181206005407.4698-1-manasi.d.navare@intel.com
      e845f099