[Intel-gfx] [PATCH v3 6/8] drm/i915/tc/tgl: Implement TC cold sequences

José Roberto de Souza jose.souza at intel.com
Tue Apr 7 21:39:58 UTC 2020


TC ports can enter in TCCOLD to save power and is required to request
to PCODE to exit this state before use or read to TC registers.

For TGL there is a new MBOX command to do that with a parameter to ask
PCODE to exit and block TCCOLD entry or unblock TCCOLD entry.

So adding a new power domain to reuse the refcount and only allow
TC cold when all TC ports are not in use.

v2:
- fixed missing case in intel_display_power_domain_str()
- moved tgl_tc_cold_request to intel_display_power.c
- renamed TGL_TC_COLD_OFF to TGL_TC_COLD_OFF_POWER_DOMAINS
- added all TC and TBT aux power domains to
TGL_TC_COLD_OFF_POWER_DOMAINS

v3:
- added one msec sleep when PCODE returns -EAGAIN
- added timeout of 5msec to not loop forever if
sandybridge_pcode_write_timeout() keeps returning -EAGAIN

BSpec: 49294
Cc: Imre Deak <imre.deak at intel.com>
Cc: Cooper Chiou <cooper.chiou at intel.com>
Cc: Kai-Heng Feng <kai.heng.feng at canonical.com>
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
---
 .../drm/i915/display/intel_display_power.c    | 104 ++++++++++++++++++
 .../drm/i915/display/intel_display_power.h    |   1 +
 drivers/gpu/drm/i915/display/intel_tc.c       |  17 ++-
 drivers/gpu/drm/i915/i915_reg.h               |   4 +
 4 files changed, 123 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index 81b968b8c397..0be6757f797c 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -151,6 +151,8 @@ intel_display_power_domain_str(enum intel_display_power_domain domain)
 		return "GT_IRQ";
 	case POWER_DOMAIN_DPLL_DC_OFF:
 		return "DPLL_DC_OFF";
+	case POWER_DOMAIN_TC_COLD_OFF:
+		return "TC_COLD_OFF";
 	default:
 		MISSING_CASE(domain);
 		return "?";
@@ -2860,6 +2862,21 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 #define TGL_AUX_I_TBT6_IO_POWER_DOMAINS (	\
 	BIT_ULL(POWER_DOMAIN_AUX_I_TBT))
 
+#define TGL_TC_COLD_OFF_POWER_DOMAINS (		\
+	BIT_ULL(POWER_DOMAIN_AUX_D)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_E)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_F)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_G)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_H)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_I)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_D_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_E_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_F_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_G_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_H_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_I_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_TC_COLD_OFF))
+
 static const struct i915_power_well_ops i9xx_always_on_power_well_ops = {
 	.sync_hw = i9xx_power_well_sync_hw_noop,
 	.enable = i9xx_always_on_power_well_noop,
@@ -3962,6 +3979,87 @@ static const struct i915_power_well_desc ehl_power_wells[] = {
 	},
 };
 
+static void
+tgl_tc_cold_request(struct drm_i915_private *i915, bool block)
+{
+	const ktime_t timeout = ktime_add_ms(ktime_get_raw(), 5);
+	u8 tries = 0;
+	int ret;
+
+	do {
+		u32 low_val = 0, high_val;
+
+		if (block)
+			high_val = TGL_PCODE_EXIT_TCCOLD_DATA_H_BLOCK_REQ;
+		else
+			high_val = TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ;
+
+		/*
+		 * Spec states that we should timeout the request after 200us
+		 * but the function below will timeout after 500us
+		 */
+		ret = sandybridge_pcode_read(i915, TGL_PCODE_TCCOLD, &low_val,
+					     &high_val);
+		if (ret == 0) {
+			if (block &&
+			    (low_val & TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED))
+				ret = -EIO;
+			else
+				break;
+		}
+
+		if (ret == -EAGAIN)
+			msleep(1);
+		else
+			tries++;
+	} while (tries < 3 && ktime_compare(timeout, ktime_get_raw()) > 0);
+
+	drm_dbg_kms(&i915->drm, "TC cold %sblock %s\n", block ? "" : "un",
+		    ret ? "failed" : "succeeded");
+}
+
+static void
+tgl_tc_cold_off_power_well_enable(struct drm_i915_private *i915,
+				  struct i915_power_well *power_well)
+{
+	tgl_tc_cold_request(i915, true);
+}
+
+static void
+tgl_tc_cold_off_power_well_disable(struct drm_i915_private *i915,
+				   struct i915_power_well *power_well)
+{
+	tgl_tc_cold_request(i915, false);
+}
+
+static void
+tgl_tc_cold_off_power_well_sync_hw(struct drm_i915_private *i915,
+				   struct i915_power_well *power_well)
+{
+	if (power_well->count > 0)
+		tgl_tc_cold_off_power_well_enable(i915, power_well);
+	else
+		tgl_tc_cold_off_power_well_disable(i915, power_well);
+}
+
+static bool
+tgl_tc_cold_off_power_well_is_enabled(struct drm_i915_private *dev_priv,
+				      struct i915_power_well *power_well)
+{
+	/*
+	 * Not the correctly implementation but there is no way to just read it
+	 * from PCODE, so returning count to avoid state mismatch errors
+	 */
+	return power_well->count;
+}
+
+static const struct i915_power_well_ops tgl_tc_cold_off_ops = {
+	.sync_hw = tgl_tc_cold_off_power_well_sync_hw,
+	.enable = tgl_tc_cold_off_power_well_enable,
+	.disable = tgl_tc_cold_off_power_well_disable,
+	.is_enabled = tgl_tc_cold_off_power_well_is_enabled,
+};
+
 static const struct i915_power_well_desc tgl_power_wells[] = {
 	{
 		.name = "always-on",
@@ -4289,6 +4387,12 @@ static const struct i915_power_well_desc tgl_power_wells[] = {
 			.hsw.irq_pipe_mask = BIT(PIPE_D),
 		},
 	},
+	{
+		.name = "TC cold off",
+		.domains = TGL_TC_COLD_OFF_POWER_DOMAINS,
+		.ops = &tgl_tc_cold_off_ops,
+		.id = DISP_PW_ID_NONE,
+	},
 };
 
 static int
diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
index da64a5edae7a..070457e7b948 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.h
+++ b/drivers/gpu/drm/i915/display/intel_display_power.h
@@ -76,6 +76,7 @@ enum intel_display_power_domain {
 	POWER_DOMAIN_MODESET,
 	POWER_DOMAIN_GT_IRQ,
 	POWER_DOMAIN_DPLL_DC_OFF,
+	POWER_DOMAIN_TC_COLD_OFF,
 	POWER_DOMAIN_INIT,
 
 	POWER_DOMAIN_NUM,
diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 74061bf9b2b9..ab87186b7e4b 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -53,16 +53,27 @@ tc_port_load_fia_params(struct drm_i915_private *i915,
 	}
 }
 
+static enum intel_display_power_domain
+tc_cold_get_power_domain(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+
+	if (INTEL_GEN(i915) == 11)
+		return intel_legacy_aux_to_power_domain(dig_port->aux_ch);
+	else
+		return POWER_DOMAIN_TC_COLD_OFF;
+}
+
 static intel_wakeref_t
 tc_cold_block(struct intel_digital_port *dig_port)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
 	enum intel_display_power_domain domain;
 
-	if (INTEL_GEN(i915) != 11 || !dig_port->tc_legacy_port)
+	if (INTEL_GEN(i915) == 11 && !dig_port->tc_legacy_port)
 		return 0;
 
-	domain = intel_legacy_aux_to_power_domain(dig_port->aux_ch);
+	domain = tc_cold_get_power_domain(dig_port);
 	return intel_display_power_get(i915, domain);
 }
 
@@ -80,7 +91,7 @@ tc_cold_unblock(struct intel_digital_port *dig_port, intel_wakeref_t wakeref)
 	if (wakeref == 0)
 		return;
 
-	domain = intel_legacy_aux_to_power_domain(dig_port->aux_ch);
+	domain = tc_cold_get_power_domain(dig_port);
 	intel_display_power_put_async(i915, domain, wakeref);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0389afa2361f..4ae1b6dfa18e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -9111,6 +9111,10 @@ enum {
 #define   ICL_PCODE_EXIT_TCCOLD			0x12
 #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
 #define   DISPLAY_IPS_CONTROL			0x19
+#define   TGL_PCODE_TCCOLD			0x26
+#define     TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED	REG_BIT(0)
+#define     TGL_PCODE_EXIT_TCCOLD_DATA_H_BLOCK_REQ	0
+#define     TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ	REG_BIT(0)
             /* See also IPS_CTL */
 #define     IPS_PCODE_CONTROL			(1 << 30)
 #define   HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL	0x1A
-- 
2.26.0



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