[v2,3/8] drm/i915/skl: Add DC5 Trigger Sequence.

Submitted by Animesh Manna on April 10, 2015, 3:11 p.m.


Message ID 1428678684-11326-1-git-send-email-animesh.manna@intel.com
State New
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Commit Message

Animesh Manna April 10, 2015, 3:11 p.m.
From: Suketu Shah <suketu.j.shah@intel.com>

Add triggers as per expectations mentioned in gen9_enable_dc5
and gen9_disable_dc5 patch.

Also call POSTING_READ for every write to a register to ensure that
its written immediately.

v1: Remove POSTING_READ calls as they've already been added in previous patches.

v2: Rebase to move all runtime pm specific changes to intel_runtime_pm.c file.

Modified as per review comments from Imre:
1] Change variable name 'dc5_allowed' to 'dc5_enabled' to correspond to relevant
2] Move the check dc5_enabled in skl_set_power_well() to disable DC5 into
   gen9_disable_DC5 which is a more appropriate place.
3] Convert checks for 'pm.dc5_enabled' and 'pm.suspended' in skl_set_power_well()
   to warnings. However, removing them for now as they'll be included in a future patch
   asserting DC-state entry/exit criteria.
4] Enable DC5, only when CSR firmware is verified to be loaded. Create new structure
   to track 'enabled' and 'deferred' status of DC5.
5] Ensure runtime PM reference is obtained, if CSR is not loaded, to avoid entering
   runtime-suspend and release it when it's loaded.
6] Protect necessary CSR-related code with locks.
7] Move CSR-loading call to runtime PM initialization, as power domains needed to be
   accessed during deferred DC5-enabling, are not initialized earlier.

v3: Rebase to latest.

Modified as per review comments from Imre:
1] Use blocking wait for CSR-loading to finish to enable DC5  for simplicity, instead of
   deferring enabling DC5 until CSR is loaded.
2] Obtain runtime PM reference during CSR-loading initialization itself as deferred DC5-
   enabling is removed and release it at the end of CSR-loading functionality.
3] Revert calling CSR-loading functionality to the beginning of i915 driver-load
   functionality to avoid any delay in loading.
4] Define another variable to track whether CSR-loading failed and use it to avoid enabling
   DC5 if it's true.
5] Define CSR-load-status accessor functions for use later.

1] Disable DC5 before enabling PG2 instead of after it.
2] DC5 was being mistaken enabled even when CSR-loading timed-out. Fix that.
3] Enable DC5-related functionality using a macro.
4] Remove dc5_enabled tracking variable and its use as it's not needed now.

1] Mark CSR failed to load where necessary in finish_csr_load function.
2] Use mutex-protected accessor function to check if CSR loaded instead of directly
   accessing the variable.
3] Prefix csr_load_status_get/set function names with intel_.

v6: rebase to latest.
v7: Rebase on top of nightly (Damien)
v8: Squashed the patch from Imre - added csr helper pointers to simplify the code. (Imre)
v9: After adding dmc ver 1.0 support rebased on top of nightly. (Animesh)
v10: Added a enum for different csr states, suggested by Imre. (Animesh)

Issue: VIZ-2819
Signed-off-by: A.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: Suketu Shah <suketu.j.shah@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Animesh Manna <animesh.manna@intel.com>
 drivers/gpu/drm/i915/i915_drv.h         |  7 +++++++
 drivers/gpu/drm/i915/intel_drv.h        |  2 ++
 drivers/gpu/drm/i915/intel_runtime_pm.c | 29 +++++++++++++++++++++++++++++
 3 files changed, 38 insertions(+)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d0325ef..841e0bb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -667,6 +667,12 @@  struct intel_uncore {
 #define for_each_fw_domain(domain__, dev_priv__, i__) \
 	for_each_fw_domain_mask(domain__, FORCEWAKE_ALL, dev_priv__, i__)
+enum csr_states {
+	FW_LOADED = 0,
 struct intel_csr {
 	const char *fw_path;
 	__be32 *dmc_payload;
@@ -674,6 +680,7 @@  struct intel_csr {
 	uint32_t mmio_count;
 	uint32_t mmioaddr[8];
 	uint32_t mmiodata[8];
+	enum csr_states states;
 #define DEV_INFO_FOR_EACH_FLAG(func, sep) \
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 9f4a6f6..5280fbe 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1058,6 +1058,8 @@  unsigned long intel_plane_obj_offset(struct intel_plane *intel_plane,
 /* intel_csr.c */
 void intel_csr_ucode_init(struct drm_device *dev);
+bool intel_csr_load_status_get(struct drm_i915_private *dev_priv);
+void intel_csr_load_status_set(struct drm_i915_private *dev_priv, bool val);
 void intel_csr_load_program(struct drm_device *dev);
 void intel_csr_ucode_fini(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
index bc6cee9..0750191 100644
--- a/drivers/gpu/drm/i915/intel_runtime_pm.c
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -49,6 +49,8 @@ 
  * present for a given platform.
+#define GEN9_ENABLE_DC5(dev) (IS_SKYLAKE(dev))
 #define for_each_power_well(i, power_well, domain_mask, power_domains)	\
 	for (i = 0;							\
 	     i < (power_domains)->power_well_count &&			\
@@ -369,6 +371,7 @@  static void gen9_disable_dc5(struct drm_i915_private *dev_priv)
 static void skl_set_power_well(struct drm_i915_private *dev_priv,
 			struct i915_power_well *power_well, bool enable)
+	struct drm_device *dev = dev_priv->dev;
 	uint32_t tmp, fuse_status;
 	uint32_t req_mask, state_mask;
 	bool is_enabled, enable_requested, check_fuse_status = false;
@@ -408,6 +411,13 @@  static void skl_set_power_well(struct drm_i915_private *dev_priv,
 	if (enable) {
 		if (!enable_requested) {
+			WARN((tmp & state_mask) &&
+				"Invalid for power well status to be enabled, unless done by the BIOS, \
+				when request is to disable!\n");
+			if (GEN9_ENABLE_DC5(dev) &&
+				power_well->data == SKL_DISP_PW_2)
+				gen9_disable_dc5(dev_priv);
 			I915_WRITE(HSW_PWR_WELL_DRIVER, tmp | req_mask);
@@ -424,6 +434,25 @@  static void skl_set_power_well(struct drm_i915_private *dev_priv,
 			I915_WRITE(HSW_PWR_WELL_DRIVER,	tmp & ~req_mask);
 			DRM_DEBUG_KMS("Disabling %s\n", power_well->name);
+			if (GEN9_ENABLE_DC5(dev) &&
+				power_well->data == SKL_DISP_PW_2) {
+				if (dev_priv->csr.states <= FW_LOADING) {
+					/*
+					* TODO: wait for a completion event or
+					* similar here instead of busy
+					* waiting using wait_for function.
+					*/
+					if (wait_for(
+						intel_csr_load_status_get(
+							dev_priv), 1000))
+						DRM_ERROR("Timed out waiting for CSR to be loaded!");
+					else
+						gen9_enable_dc5(dev_priv);
+				} else {
+					DRM_ERROR("Cannot enable DC5 as CSR failed to load!");
+				}
+			}