After the split-out of crtc locks from the big mode_config.mutex
there's still two major areas it protects:
- Various connector probe states, like connector->status, EDID
properties, probed mode lists and similar information.
- The links from connector->encoder and encoder->crtc and other
modeset-relevant connector state (e.g. properties which control the
panel fitter).
The later is used by modeset operations. But they don't really care
about the former since it's allowed to e.g. enable a disconnected VGA
output or with a mode not in the probed list.
Thus far this hasn't been a problem, but for the atomic modeset
conversion Rob Clark needs to convert all modeset relevant locks into
w/w locks. This is required because the order of acquisition is
determined by how userspace supplies the atomic modeset data. This has
run into troubles in the detect path since the i915 load detect code
needs _both_ protections offered by the mode_config.mutex: It updates
probe state and it needs to change the modeset configuration to enable
the temporary load detect pipe.
The big deal here is that for the probe/detect users of this lock a
plain mutex fits best, but for atomic modesets we really want a w/w
mutex. To fix this lets split out a new connection_mutex lock for the
modeset relevant parts.
For simplicity I've decided to only add one additional lock for all
connector/encoder links and modeset configuration states. We have
piles of different modeset objects in addition to those (like bridges
or panels), so adding per-object locks would be much more effort.
Also, we're guaranteed (at least for now) to do a full modeset if we
need to acquire this lock. Which means that fine-grained locking is
fairly irrelevant compared to the amount of time the full modeset will
take.
I've done a full audit, and there's just a few things that justify
special focus:
- Locking in drm_sysfs.c is almost completely absent. We should
sprinkle mode_config.connection_mutex over this file a bit, but
since it already lacks mode_config.mutex this patch wont make the
situation any worse. This is material for a follow-up patch.
- omap has a omap_framebuffer_flush function which walks the
connector->encoder->crtc links and is called from many contexts.
Some look like they don't acquire mode_config.mutex, so this is
already racy. Again fixing this is material for a separate patch.
- The radeon hot_plug function to retrain DP links looks at
connector->dpms. Currently this happens without any locking, so is
already racy. I think radeon_hotplug_work_func should gain
mutex_lock/unlock calls for the mode_config.connection_mutex.
- Same applies to i915's intel_dp_hot_plug. But again, this is already
racy.
- i915 load_detect code needs to acquire this lock. Which means the
w/w dance due to Rob's work will be nicely contained to _just_ this
function.
I've added fixme comments everywhere where it looks suspicious but in
the sysfs code. After a quick irc discussion with Dave Airlie it
sounds like the lack of locking in there is due to sysfs cleanup fun
at module unload.
v1: original (only compile tested)
v2: missing mutex_init(), etc (from Rob Clark)
v3: i915 needs more care in the conversion:
- Protect the edp pp logic with the connection_mutex.
- Use connection_mutex in the backlight code due to
get_pipe_from_connector.
- Use drm_modeset_lock_all in suspend/resume paths.
- Update lock checks in the overlay code.
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Print a warning when the user tries to rotate a non-TILER framebuffer.
Also set the rotation to 0, to avoid constant flood of the warnings in
case of page flipping.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
* 'msm-next' of git://people.freedesktop.org/~robclark/linux:
drm/omap: Don't dereference list head when the connectors list is empty
drm/msm/mdp: add timeout for irq wait
drm/msm: validate flags, etc
drm/msm: use componentised device support
drm/msm: add chip-id param
drm/msm: crank down gpu when inactive
drm/msm: spin helper
drm/msm: add hang_debug module param
drm/msm: hdmi audio support
Now that CRTC's have a primary plane, there's no need to track the
framebuffer in the CRTC. Replace all references to the CRTC fb with the
primary plane's fb.
This patch was generated by the Coccinelle semantic patching tool using
the following rules:
@@ struct drm_crtc C; @@
- (C).fb
+ C.primary->fb
@@ struct drm_crtc *C; @@
- (C)->fb
+ C->primary->fb
v3: Generate patch via coccinelle. Actual removal of crtc->fb has been
moved to a subsequent patch.
v2: Fixup several lingering crtc->fb instances that were missed in the
first patch iteration. [Rob Clark]
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
The connectors list iterator returns the list head when the list is
empty. Fix it by returning NULL in that case.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Not all drivers will need take all the modeset locks for dirtyfb, so
push the locking down to the drivers.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
And simplify how we hold a ref+pin to what is being scanned out by using
fb refcnt'ing. The previous logic pre-dated fb refcnt, and as a result
was less straightforward than it could have been. By holding a ref to
the fb, we don't have to care about how many plane's there are and
holding a ref to each color plane's bo.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Pull drm merge from Dave Airlie:
"Highlights:
- TI LCD controller KMS driver
- TI OMAP KMS driver merged from staging
- drop gma500 stub driver
- the fbcon locking fixes
- the vgacon dirty like zebra fix.
- open firmware videomode and hdmi common code helpers
- major locking rework for kms object handling - pageflip/cursor
won't block on polling anymore!
- fbcon helper and prime helper cleanups
- i915: all over the map, haswell power well enhancements, valleyview
macro horrors cleaned up, killing lots of legacy GTT code,
- radeon: CS ioctl unification, deprecated UMS support, gpu reset
rework, VM fixes
- nouveau: reworked thermal code, external dp/tmds encoder support
(anx9805), fences sleep instead of polling,
- exynos: all over the driver fixes."
Lovely conflict in radeon/evergreen_cs.c between commit de0babd60d
("drm/radeon: enforce use of radeon_get_ib_value when reading user cmd")
and the new changes that modified that evergreen_dma_cs_parse()
function.
* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (508 commits)
drm/tilcdc: only build on arm
drm/i915: Revert hdmi HDP pin checks
drm/tegra: Add list of framebuffers to debugfs
drm/tegra: Fix color expansion
drm/tegra: Split DC_CMD_STATE_CONTROL register write
drm/tegra: Implement page-flipping support
drm/tegra: Implement VBLANK support
drm/tegra: Implement .mode_set_base()
drm/tegra: Add plane support
drm/tegra: Remove bogus tegra_framebuffer structure
drm: Add consistency check for page-flipping
drm/radeon: Use generic HDMI infoframe helpers
drm/tegra: Use generic HDMI infoframe helpers
drm: Add EDID helper documentation
drm: Add HDMI infoframe helpers
video: Add generic HDMI infoframe helpers
drm: Add some missing forward declarations
drm: Move mode tables to drm_edid.c
drm: Remove duplicate drm_mode_cea_vic()
gma500: Fix n, m1 and m2 clock limits for sdvo and lvds
...
Now that the omapdss interface has been reworked so that omapdrm can use
dispc directly, we have been able to fix the remaining functional kms
issues with omapdrm. And in the mean time the PM sequencing and many
other of that open issues have been solved. So I think it makes sense
to finally move omapdrm out of staging.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Daniel Vetter