drm/i915/psr: Control PSR interrupts via debugfs

Interrupts other than the one for AUX errors are required only for debug,
so unmask them via debugfs when the user requests debug.

User can make such a request with
echo 1 > <DEBUG_FS>/dri/0/i915_edp_psr_debug

There are no locks to serialize PSR debug enabling from
irq_postinstall() and debugfs for simplicity. As irq_postinstall() is
called only during module initialization/resume and IGT subtests
aren't expected to modify PSR debug at those times, we should be safe.

v2: Unroll loops (Ville)
    Avoid resetting error mask bits.

v3: Unmask interrupts in postinstall() if debug was still enabled.
    Avoid RMW (Ville)

v4: Avoid extra IMR write introduced in the previous version.(Jose)
    Style changes, renames (Jose).

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Reviewed-by: Jose Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180405013717.24254-1-dhinakaran.pandiyan@intel.com

1 files changed, 58 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 69a5b276f4d8..ae6a916523c2 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -93,6 +93,64 @@ static void psr_aux_io_power_put(struct intel_dp *intel_dp)
 	intel_display_power_put(dev_priv, psr_aux_domain(intel_dp));
 }
 
+void intel_psr_irq_control(struct drm_i915_private *dev_priv, bool debug)
+{
+	u32 debug_mask, mask;
+
+	/* No PSR interrupts on VLV/CHV */
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
+		return;
+
+	mask = EDP_PSR_ERROR(TRANSCODER_EDP);
+	debug_mask = EDP_PSR_POST_EXIT(TRANSCODER_EDP) |
+		     EDP_PSR_PRE_ENTRY(TRANSCODER_EDP);
+
+	if (INTEL_GEN(dev_priv) >= 8) {
+		mask |= EDP_PSR_ERROR(TRANSCODER_A) |
+			EDP_PSR_ERROR(TRANSCODER_B) |
+			EDP_PSR_ERROR(TRANSCODER_C);
+
+		debug_mask |= EDP_PSR_POST_EXIT(TRANSCODER_A) |
+			      EDP_PSR_PRE_ENTRY(TRANSCODER_A) |
+			      EDP_PSR_POST_EXIT(TRANSCODER_B) |
+			      EDP_PSR_PRE_ENTRY(TRANSCODER_B) |
+			      EDP_PSR_POST_EXIT(TRANSCODER_C) |
+			      EDP_PSR_PRE_ENTRY(TRANSCODER_C);
+	}
+
+	if (debug)
+		mask |= debug_mask;
+
+	WRITE_ONCE(dev_priv->psr.debug, debug);
+	I915_WRITE(EDP_PSR_IMR, ~mask);
+}
+
+void intel_psr_irq_handler(struct drm_i915_private *dev_priv, u32 psr_iir)
+{
+	u32 transcoders = BIT(TRANSCODER_EDP);
+	enum transcoder cpu_transcoder;
+
+	if (INTEL_GEN(dev_priv) >= 8)
+		transcoders |= BIT(TRANSCODER_A) |
+			       BIT(TRANSCODER_B) |
+			       BIT(TRANSCODER_C);
+
+	for_each_cpu_transcoder_masked(dev_priv, cpu_transcoder, transcoders) {
+		/* FIXME: Exit PSR and link train manually when this happens. */
+		if (psr_iir & EDP_PSR_ERROR(cpu_transcoder))
+			DRM_DEBUG_KMS("[transcoder %s] PSR aux error\n",
+				      transcoder_name(cpu_transcoder));
+
+		if (psr_iir & EDP_PSR_PRE_ENTRY(cpu_transcoder))
+			DRM_DEBUG_KMS("[transcoder %s] PSR entry attempt in 2 vblanks\n",
+				      transcoder_name(cpu_transcoder));
+
+		if (psr_iir & EDP_PSR_POST_EXIT(cpu_transcoder))
+			DRM_DEBUG_KMS("[transcoder %s] PSR exit completed\n",
+				      transcoder_name(cpu_transcoder));
+	}
+}
+
 static bool intel_dp_get_y_coord_required(struct intel_dp *intel_dp)
 {
 	uint8_t psr_caps = 0;