Merge the modeset-rework, basic conversion into drm-intel-next

As a quick reference I'll detail the motivation and design of the new code a
bit here (mostly stitched together from patchbomb announcements and commits
introducing the new concepts).

The crtc helper code has the fundamental assumption that encoders and crtcs can
be enabled/disabled in any order, as long as we take care of depencies (which
means that enabled encoders need an enabled crtc to feed them data,
essentially).

Our hw works differently. We already have tons of ugly cases where crtc code
enables encoder hw (or encoder->mode_set enables stuff that should only be
enabled in enocder->commit) to work around these issues. But on the disable
side we can't pull off similar tricks - there we actually need to rework the
modeset sequence that controls all this. And this is also the real motivation
why I've finally undertaken this rewrite: eDP on my shiny new Ivybridge
Ultrabook is broken, and it's broken due to the wrong disable sequence ...

The new code introduces a few interfaces and concepts:

- Add new encoder->enable/disable functions which are directly called from the
crtc->enable/disable function. This ensures that the encoder's can be
enabled/disabled at a very specific in the modeset sequence, controlled by our
platform specific code (instead of the crtc helper code calling them at a time
it deems convenient).

- Rework the dpms code - our code has mostly 1:1 connector:encoder mappings and
does support cloning on only a few encoders, so we can simplify things quite a
bit.

- Also only ever disable/enable the entire output pipeline. This ensures that
we obey the right sequence of enabling/disabling things, trying to be clever
here mostly just complicates the code and results in bugs. For cloneable
encoders this requires a bit of special handling to ensure that outputs can
still be disabled individually, but it simplifies the common case.

- Add infrastructure to read out the current hw state. No amount of careful
ordering will help us if we brick the hw on the initial modeset setup. Which
could happen if we just randomly disable things, oblivious to the state set up
by the bios. Hence we need to be able to read that out. As a benefit, we grow a
few generic functions useful to cross-check our modeset code with actual hw
state.

With all this in place, we can copy&paste the crtc helper code into the
drm/i915 driver and start to rework it:

- As detailed above, the new code only disables/enables an entire output pipe.
As a preparation for global mode-changes (e.g. reassigning shared resources) it
keeps track of which pipes need to be touched by a set of bitmasks.

- To ensure that we correctly disable the current display pipes, we need to
know the currently active connector/encoder/crtc linking. The old crtc helper
simply overwrote these links with the new setup, the new code stages the new
links in ->new_* pointers. Those get commited to the real linking pointers once
the old output configuration has been torn down, before the ->mode_set
callbacks are called.

- Finally the code adds tons of self-consistency checks by employing the new hw
state readout functions to cross-check the actual hw state with what the
datastructure think it should be. These checks are done both after every
modeset and after the hw state has been read out and sanitized at boot/resume
time. All these checks greatly helped in tracking down regressions and bugs in
the new code.

With this new basis, a lot of cleanups and improvements to the code are now
possible (besides the DP fixes that ultimately made me write this), but not yet
done:

- I think we should create struct intel_mode and use it as the adjusted mode
everywhere to store little pieces like needs_tvclock, pipe dithering values or
dp link parameters. That would still be a layering violation, but at least we
wouldn't need to recompute these kinds of things in intel_display.c. Especially
the port bpc computation needed for selecting the pipe bpc and dithering
settings in intel_display.c is rather gross.

- In a related rework we could implement ->mode_valid in terms of ->mode_fixup
in a generic way - I've hunted down too many bugs where ->mode_valid did the
right thing, but ->mode_fixup didn't. Or vice versa, resulting in funny bugs
for user-supplied modes.

- Ditch the idea to rework the hdp handling in the common crtc helper code and
just move things to i915.ko. Which would rid us of the ->detect crtc helper
dependencies.

- LVDS wire pair and pll enabling is all done in the crtc->mode_set function
currently. We should be able to move this to the crtc_enable callbacks (or in
the case of the LVDS wire pair enabling, into some encoder callback).

Last, but not least, this new code should also help in enabling a few neat
features: The hw state readout code prepares (but there are still big pieces
missing) for fastboot, i.e. avoiding the inital modeset at boot-up and just
taking over the configuration left behind by the bios. We also should be able
to extend the configuration checks in the beginning of the modeset sequence and
make better decisions about shared resources (which is the entire point behind
the atomic/global modeset ioctl).

Tested-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: Ben Widawsky <ben@bwidawsk.net>
Tested-by: Damien Lespiau <damien.lespiau@intel.com>
Tested-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
Acked-by: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
Tested-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Acked-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 55 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 3f7eefc5d976..4f2b2d6a2489 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -137,6 +137,12 @@ struct intel_fbdev {
 
 struct intel_encoder {
 	struct drm_encoder base;
+	/*
+	 * The new crtc this encoder will be driven from. Only differs from
+	 * base->crtc while a modeset is in progress.
+	 */
+	struct intel_crtc *new_crtc;
+
 	int type;
 	bool needs_tv_clock;
 	/*
@@ -144,13 +150,33 @@ struct intel_encoder {
 	 * simple flag is enough to compute the possible_clones mask.
 	 */
 	bool cloneable;
+	bool connectors_active;
 	void (*hot_plug)(struct intel_encoder *);
+	void (*enable)(struct intel_encoder *);
+	void (*disable)(struct intel_encoder *);
+	/* Read out the current hw state of this connector, returning true if
+	 * the encoder is active. If the encoder is enabled it also set the pipe
+	 * it is connected to in the pipe parameter. */
+	bool (*get_hw_state)(struct intel_encoder *, enum pipe *pipe);
 	int crtc_mask;
 };
 
 struct intel_connector {
 	struct drm_connector base;
+	/*
+	 * The fixed encoder this connector is connected to.
+	 */
 	struct intel_encoder *encoder;
+
+	/*
+	 * The new encoder this connector will be driven. Only differs from
+	 * encoder while a modeset is in progress.
+	 */
+	struct intel_encoder *new_encoder;
+
+	/* Reads out the current hw, returning true if the connector is enabled
+	 * and active (i.e. dpms ON state). */
+	bool (*get_hw_state)(struct intel_connector *);
 };
 
 struct intel_crtc {
@@ -158,8 +184,12 @@ struct intel_crtc {
 	enum pipe pipe;
 	enum plane plane;
 	u8 lut_r[256], lut_g[256], lut_b[256];
-	int dpms_mode;
-	bool active; /* is the crtc on? independent of the dpms mode */
+	/*
+	 * Whether the crtc and the connected output pipeline is active. Implies
+	 * that crtc->enabled is set, i.e. the current mode configuration has
+	 * some outputs connected to this crtc.
+	 */
+	bool active;
 	bool primary_disabled; /* is the crtc obscured by a plane? */
 	bool lowfreq_avail;
 	struct intel_overlay *overlay;
@@ -311,7 +341,6 @@ struct intel_dp {
 	enum hdmi_force_audio force_audio;
 	enum port port;
 	uint32_t color_range;
-	int dpms_mode;
 	uint8_t link_bw;
 	uint8_t lane_count;
 	uint8_t dpcd[DP_RECEIVER_CAP_SIZE];
@@ -413,10 +442,27 @@ extern void intel_panel_disable_backlight(struct drm_device *dev);
 extern void intel_panel_destroy_backlight(struct drm_device *dev);
 extern enum drm_connector_status intel_panel_detect(struct drm_device *dev);
 
+struct intel_set_config {
+	struct drm_encoder **save_connector_encoders;
+	struct drm_crtc **save_encoder_crtcs;
+
+	bool fb_changed;
+	bool mode_changed;
+};
+
+extern bool intel_set_mode(struct drm_crtc *crtc, struct drm_display_mode *mode,
+			   int x, int y, struct drm_framebuffer *old_fb);
+extern void intel_modeset_disable(struct drm_device *dev);
 extern void intel_crtc_load_lut(struct drm_crtc *crtc);
-extern void intel_encoder_prepare(struct drm_encoder *encoder);
-extern void intel_encoder_commit(struct drm_encoder *encoder);
+extern void intel_crtc_update_dpms(struct drm_crtc *crtc);
+extern void intel_encoder_noop(struct drm_encoder *encoder);
 extern void intel_encoder_destroy(struct drm_encoder *encoder);
+extern void intel_encoder_dpms(struct intel_encoder *encoder, int mode);
+extern bool intel_encoder_check_is_cloned(struct intel_encoder *encoder);
+extern void intel_connector_dpms(struct drm_connector *, int mode);
+extern bool intel_connector_get_hw_state(struct intel_connector *connector);
+extern void intel_modeset_check_state(struct drm_device *dev);
+
 
 static inline struct intel_encoder *intel_attached_encoder(struct drm_connector *connector)
 {
@@ -523,7 +569,10 @@ extern void intel_disable_gt_powersave(struct drm_device *dev);
 extern void gen6_gt_check_fifodbg(struct drm_i915_private *dev_priv);
 extern void ironlake_teardown_rc6(struct drm_device *dev);
 
-extern void intel_ddi_dpms(struct drm_encoder *encoder, int mode);
+extern void intel_enable_ddi(struct intel_encoder *encoder);
+extern void intel_disable_ddi(struct intel_encoder *encoder);
+extern bool intel_ddi_get_hw_state(struct intel_encoder *encoder,
+				   enum pipe *pipe);
 extern void intel_ddi_mode_set(struct drm_encoder *encoder,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode);