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

1 files changed, 0 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c5f36b4f4f16..5c732f87b9ce 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -738,12 +738,6 @@ struct intel_uncore {
 #define CSR_VERSION_MAJOR(version)	((version) >> 16)
 #define CSR_VERSION_MINOR(version)	((version) & 0xffff)
 
-enum csr_state {
-	FW_UNINITIALIZED = 0,
-	FW_LOADED,
-	FW_FAILED
-};
-
 struct intel_csr {
 	const char *fw_path;
 	uint32_t *dmc_payload;
@@ -752,7 +746,6 @@ struct intel_csr {
 	uint32_t mmio_count;
 	uint32_t mmioaddr[8];
 	uint32_t mmiodata[8];
-	enum csr_state state;
 };
 
 #define DEV_INFO_FOR_EACH_FLAG(func, sep) \
@@ -1709,9 +1702,6 @@ struct drm_i915_private {
 
 	struct intel_csr csr;
 
-	/* Display CSR-related protection */
-	struct mutex csr_lock;
-
 	struct intel_gmbus gmbus[GMBUS_NUM_PINS];
 
 	/** gmbus_mutex protects against concurrent usage of the single hw gmbus