drm/i915/dmc: Assert DMC is loaded harder

Currently we have some asserts to make sure the main DMC has been
loaded. Add similar asserts for the pipe DMCs. And we might as well
just check all the mmio registers the firmware has asked us to
initialize. That also covers the hardcoded SSP/HTP registers we were
checking for the main DMC.

TODO: Maybe always configure DMC_EVT_CTL_ENABLE the way the firmware
      has it set so that we wouldn't need to special case in the assert?

v2: Also assert in intel_dmc_load_program()

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250617170759.19552-8-ville.syrjala@linux.intel.com

1 files changed, 45 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
index 2a40a09dca94..3bd1220b72b3 100644
--- a/drivers/gpu/drm/i915/display/intel_dmc.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc.c
@@ -607,6 +607,46 @@ static void dmc_load_program(struct intel_display *display, enum intel_dmc_id dm
 	dmc_load_mmio(display, dmc_id);
 }
 
+static void assert_dmc_loaded(struct intel_display *display,
+			      enum intel_dmc_id dmc_id)
+{
+	struct intel_dmc *dmc = display_to_dmc(display);
+	u32 expected, found;
+	int i;
+
+	if (!is_valid_dmc_id(dmc_id) || !has_dmc_id_fw(display, dmc_id))
+		return;
+
+	found = intel_de_read(display, DMC_PROGRAM(dmc->dmc_info[dmc_id].start_mmioaddr, 0));
+	expected = dmc->dmc_info[dmc_id].payload[0];
+
+	drm_WARN(display->drm, found != expected,
+		 "DMC %d program storage start incorrect (expected 0x%x, current 0x%x)\n",
+		 dmc_id, expected, found);
+
+	for (i = 0; i < dmc->dmc_info[dmc_id].mmio_count; i++) {
+		i915_reg_t reg = dmc->dmc_info[dmc_id].mmioaddr[i];
+
+		found = intel_de_read(display, reg);
+		expected = dmc_mmiodata(display, dmc, dmc_id, i);
+
+		/* once set DMC_EVT_CTL_ENABLE can't be cleared :/ */
+		if (is_dmc_evt_ctl_reg(display, dmc_id, reg)) {
+			found &= ~DMC_EVT_CTL_ENABLE;
+			expected &= ~DMC_EVT_CTL_ENABLE;
+		}
+
+		drm_WARN(display->drm, found != expected,
+			 "DMC %d mmio[%d]/0x%x incorrect (expected 0x%x, current 0x%x)\n",
+			 dmc_id, i, i915_mmio_reg_offset(reg), expected, found);
+	}
+}
+
+void assert_main_dmc_loaded(struct intel_display *display)
+{
+	assert_dmc_loaded(display, DMC_FW_MAIN);
+}
+
 static bool need_pipedmc_load_program(struct intel_display *display)
 {
 	/* On TGL/derivatives pipe DMC state is lost when PG1 is disabled */
@@ -671,6 +711,8 @@ void intel_dmc_enable_pipe(struct intel_display *display, enum pipe pipe)
 	else if (need_pipedmc_load_mmio(display, pipe))
 		dmc_load_mmio(display, dmc_id);
 
+	assert_dmc_loaded(display, dmc_id);
+
 	if (DISPLAY_VER(display) >= 20) {
 		intel_de_write(display, PIPEDMC_INTERRUPT(pipe), pipedmc_interrupt_mask(display));
 		intel_de_write(display, PIPEDMC_INTERRUPT_MASK(pipe), ~pipedmc_interrupt_mask(display));
@@ -780,8 +822,10 @@ void intel_dmc_load_program(struct intel_display *display)
 
 	pipedmc_clock_gating_wa(display, true);
 
-	for_each_dmc_id(dmc_id)
+	for_each_dmc_id(dmc_id) {
 		dmc_load_program(display, dmc_id);
+		assert_dmc_loaded(display, dmc_id);
+	}
 
 	power_domains->dc_state = 0;
 
@@ -812,20 +856,6 @@ void intel_dmc_disable_program(struct intel_display *display)
 	pipedmc_clock_gating_wa(display, false);
 }
 
-void assert_dmc_loaded(struct intel_display *display)
-{
-	struct intel_dmc *dmc = display_to_dmc(display);
-
-	drm_WARN_ONCE(display->drm, !dmc, "DMC not initialized\n");
-	drm_WARN_ONCE(display->drm, dmc &&
-		      !intel_de_read(display, DMC_PROGRAM(dmc->dmc_info[DMC_FW_MAIN].start_mmioaddr, 0)),
-		      "DMC program storage start is NULL\n");
-	drm_WARN_ONCE(display->drm, !intel_de_read(display, DMC_SSP_BASE),
-		      "DMC SSP Base Not fine\n");
-	drm_WARN_ONCE(display->drm, !intel_de_read(display, DMC_HTP_SKL),
-		      "DMC HTP Not fine\n");
-}
-
 static bool fw_info_matches_stepping(const struct intel_fw_info *fw_info,
 				     const struct stepping_info *si)
 {