drm/i915/gen9: Remove csr.state, csr_lock and related code.
This removes two anti-patterns:
- Locking shouldn't be used to synchronize with async work (of any
form, whether callbacks, workers or other threads). This is what the
mutex_lock/unlock seems to have been for in intel_csr_load_program.
Instead ordering should be ensured with the generic
wait_for_completion()/complete(). Or more specific functions
provided by the core kernel like e.g.
flush_work()/cancel_work_sync() in the case of synchronizing with a
work item.
- Don't invent own completion like the following code did with the
(already removed) wait_for(csr_load_status_get()) pattern - it's
really hard to get these right when you want them to be _really_
correct (and be fast) in all cases. Furthermore it's easier to read
code using the well-known primitives than new ones using
non-standard names.
Before enabling/disabling DC6 check if the firmware is loaded
successfully. This is guaranteed during runtime s/r, since otherwise we
don't enable RPM, but not during system s/r.
Note that it's still unclear whether we need to enable/disable DC6
during system s/r, until that's clarified, keep the current behavior and
enable/disable DC6.
Also after this patch there is a race during system s/r where the
firmware may not be loaded yet, that's addressed in an upcoming patch.
v2-v3:
- unchanged
v4:
- rebased on latest drm-intel-nightly
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
[imre: added code and note about checking if the firmware loaded ok,
before enabling/disabling it]
Reviewed-by: Animesh Manna <animesh.manna@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Tested-by: Daniel Stone <daniels@collabora.com> # SKL
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447341037-2623-1-git-send-email-imre.deak@intel.com
6 files changed