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

Animesh Manna
2015-04-10T14:15:30Z

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
functions.
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.

v4:
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.

v5:
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(+)

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,
+ FW_LOADING,
+ FW_FAILED
+};
+
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) &&
+ !I915_READ(HSW_PWR_WELL_BIOS),
+ "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);
POSTING_READ(HSW_PWR_WELL_DRIVER);
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!");
+ }
+ }
}
}

--
2.0.2