mirror of https://gitee.com/openkylin/linux.git
4 Commits
Author | SHA1 | Message | Date |
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Daniel Vetter | c7eb76f493 |
drm/atomic: Ensure that drm_connector_index is stable
I've totally forgotten that with DP MST connectors can now be hotplugged. And failed to adapt Rob's drm_atomic_state code (which predates connector hotplugging) to the new realities. The first step is to make sure that the connector indices used to access the arrays of pointers are stable. The connection mutex gives us enough guarantees for that, which means we won't unecessarily block on concurrent modesets or background probing. So add a locking WARN_ON and shuffle the code slightly to make sure we always hold the right lock. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com> |
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Daniel Vetter | 4d02e2de0e |
drm: Per-plane locking
Turned out to be much simpler on top of my latest atomic stuff than what I've feared. Some details: - Drop the modeset_lock_all snakeoil in drm_plane_init. Same justification as for the equivalent change in drm_crtc_init done in commit |
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Daniel Vetter | 321ebf04dc |
drm/atomic: Refcounting for plane_state->fb
So my original plan was that the drm core refcounts framebuffers like with the legacy ioctls. But that doesn't work for a bunch of reasons: - State objects might live longer than until the next fb change happens for a plane. For example delayed cleanup work only happens _after_ the pageflip ioctl has completed. So this definitely doesn't work without the plane state holding its own references. - The other issue is transition from legacy to atomic implementations, where the driver works under a mix of both worlds. Which means legacy paths might not properly update the ->fb pointer under plane->state->fb. Which is a bit a problem when then someone comes around and _does_ try to clean it up when it's long gone. The second issue is just a bit a transition bug, since drivers should update plane->state->fb in all the paths that aren't converted yet. But a bit more robustness for the transition can't hurt - we pull similar tricks with cleaning up the old fb in the transitional helpers already. The pattern for drivers that transition is if (plane->state) drm_atomic_set_fb_for_plane(plane->state, plane->fb); inserted after the fb update has logically completed at the end of ->set_config (or ->set_base/mode_set if using the crtc helpers), ->page_flip, ->update_plane or any other entry point which updates plane->fb. v2: Update kerneldoc - copypasta fail. v3: Fix spelling in the commit message (Sean). Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> |
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Daniel Vetter | cc4ceb484b |
drm: Global atomic state handling
Some differences compared to Rob's patches again: - Dropped the committed and checked booleans. Checking will be internally enforced by always calling ->atomic_check before ->atomic_commit. And async handling needs to be solved differently because the current scheme completely side-steps ww mutex deadlock avoidance (and so either reinvents a new deadlock avoidance wheel or like the current code just deadlocks). - State for connectors needed to be added, since now they have a full-blown drm_connector_state (so that drivers have something to attach their own stuff to). - Refcounting is gone. I plane to solve async updates differently, since the lock-passing scheme doesn't cut it (since it abuses ww mutexes). Essentially what we need for async is a simple ownership transfer from the caller to the driver. That doesn't need full-blown refcounting. - The acquire ctx is a pointer. Real atomic callers should have that on their stack, legacy entry points need to put the right one (obtained by drm_modeset_legacy_acuire_ctx) in there. - I've dropped all hooks except check/commit. All the begin/end handling is done by core functions and is the same. - commit/check are just thin wrappers that ensure that ->check is always called. - To help out with locking in the legacy implementations I've added a helper to just grab all locks in the backoff case. v2: Add notices that check/commit can fail with EDEADLK. v3: - More consistent naming for state_alloc. - Add state_clear which is needed for backoff and retry. v4: Planes/connectors can switch between crtcs, and we need to be careful that we grab the state (and locks) for both the old and new crtc. Improve the interface functions to ensure this. v5: Add functions to grab affected connectors for a crtc and to recompute the crtc->enable state. This is useful for both helper and atomic ioctl code when e.g. removing a connector. v6: Squash in fixup from Fengguang to use ERR_CAST. v7: Add debug output. v8: Make checkpatch happy about kcalloc argument ordering. v9: Improve kerneldoc in drm_crtc.h v10: - Fix another kcalloc argument misorder I've missed. - More polish for kerneldoc. v11: Clarify the ownership rules for the state object. The new rule is that a successful drm_atomic_commit (whether synchronous or asnyc) always inherits the state and is responsible for the clean-up. That way async and sync ->commit functions are more similar. v12: A few bugfixes: - Assign state->state pointers correctly when grabbing state objects - we need to link them up with the global state. - Handle a NULL crtc in set_crtc_for_plane to simplify code flow a bit for the callers of this function. v13: Review from Sean: - kerneldoc spelling fixes - Don't overallocate states->planes. - Handle NULL crtc in set_crtc_for_connector. v14: Sprinkle __must_check over all functions which do wait/wound locking to make sure callers don't forget this. Since I have ;-) v15: Be more explicit in the kerneldoc when functions can return -EDEADLK what to do. And that every other -errno is fatal. v16: Indent with tabs instead of space, spotted by Ander. v17: Review from Thierry, small kerneldoc and other naming polish. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Ander Conselvan de Oliveira <conselvan2@gmail.com> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Sean Paul <seanpaul@chromium.org> Cc: Matt Roper <matthew.d.roper@intel.com> Reviewed-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> |