drm/i915: make PC8 be part of runtime PM suspend/resume
Currently, when our driver becomes idle for i915.pc8_timeout (default:
5s) we enable PC8, so we save some power, but not everything we can.
Then, while PC8 is enabled, if we stay idle for more
autosuspend_delay_ms (default: 10s) we'll enter runtime PM and put the
graphics device in D3 state, saving even more power. The two features
are separate things with increasing levels of power savings, but if we
disable PC8 we'll never get into D3.
While from the modularity point of view it would be nice to keep these
features as separate, we have reasons to merge them:
- We are not aware of anybody wanting a "PC8 without D3" environment.
- If we keep both features as separate, we'll have to to test both
PC8 and PC8+D3 code paths. We're already having a major pain to
make QA do automated testing of just one thing, testing both paths
will cost even more.
- Only Haswell+ supports PC8, so if we want to add runtime PM support
to, for example, IVB, we'll have to copy some code from the PC8
feature to runtime PM, so merging both features as a single thing
will make it easier for enabling runtime PM on other platforms.
This patch only does the very basic steps required to have PC8 and
runtime PM merged on a single feature: the next patches will take care
of cleaning up everything.
v2: - Rebase.
v3: - Rebase.
- Fully remove the deprecated i915 params since Daniel doesn't
consider them as part of the ABI.
v4: - Rebase.
- Fix typo in the commit message.
v5: - Rebase, again.
- Add a huge comment explaining the different forcewake usage
(Chris, Daniel).
- Use open-coded forcewake functions (Daniel).
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a937711..0e5148a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1339,6 +1339,10 @@
/*
* This struct tracks the state needed for the Package C8+ feature.
*
+ * TODO: we're merging the Package C8+ feature with the runtime PM support. To
+ * avoid having to update the documentation at each patch of the series, we'll
+ * do a final update at the end.
+ *
* Package states C8 and deeper are really deep PC states that can only be
* reached when all the devices on the system allow it, so even if the graphics
* device allows PC8+, it doesn't mean the system will actually get to these
@@ -1392,7 +1396,6 @@
bool enabled;
int disable_count;
struct mutex lock;
- struct delayed_work enable_work;
struct {
uint32_t deimr;
@@ -2095,8 +2098,6 @@
unsigned int preliminary_hw_support;
int disable_power_well;
int enable_ips;
- int enable_pc8;
- int pc8_timeout;
int invert_brightness;
int enable_cmd_parser;
/* leave bools at the end to not create holes */