[Intel-gfx] [PATCH v2 22/22] drm/i915/audio: Resume HSW/BDW HDA controller around ELD access

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

On HSW/BDW the hardware ELD buffer does not work if the controller
is suspended. I'm not 100% which thing in there is needed to make it
work (at least just forcing the controller into D0 with setpci is
not enough). But a full runtime resume seems to do the trick here
at least, and so far it looks like this doesn't even deadlock or
anything.

Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>
Cc: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Cc: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_audio.c | 38 ++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
index 328c47719fd8..467f3f260969 100644
--- a/drivers/gpu/drm/i915/display/intel_audio.c
+++ b/drivers/gpu/drm/i915/display/intel_audio.c
@@ -23,6 +23,7 @@
 
 #include <linux/component.h>
 #include <linux/kernel.h>
+#include <linux/pm_runtime.h>
 
 #include <drm/drm_edid.h>
 #include <drm/i915_component.h>
@@ -480,6 +481,16 @@ hsw_audio_config_update(struct intel_encoder *encoder,
 		hsw_hdmi_audio_config_update(encoder, crtc_state);
 }
 
+static struct pci_dev *hsw_hda_controller(struct drm_i915_private *i915)
+{
+	int domain = pci_domain_nr(to_pci_dev(i915->drm.dev)->bus);
+
+	if (!IS_HASWELL(i915) && !IS_BROADWELL(i915))
+		return NULL;
+
+	return pci_get_domain_bus_and_slot(domain, 0, PCI_DEVFN(3, 0));
+}
+
 static int hsw_eld_buffer_size(struct drm_i915_private *i915,
 			       enum transcoder cpu_transcoder)
 {
@@ -497,8 +508,14 @@ static void hsw_audio_codec_get_config(struct intel_encoder *encoder,
 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
 	u32 *eld = (u32 *)crtc_state->eld;
 	int eld_buffer_size, len, i;
+	struct pci_dev *hsw_hdac;
 	u32 tmp;
 
+	/* on HSW/BDW ELD access doesn't work if the HDA controller is supended */
+	hsw_hdac = hsw_hda_controller(i915);
+	if (hsw_hdac)
+		pm_runtime_get_sync(&hsw_hdac->dev);
+
 	tmp = intel_de_read(i915, HSW_AUD_PIN_ELD_CP_VLD);
 	if ((tmp & AUDIO_ELD_VALID(cpu_transcoder)) == 0)
 		return;
@@ -511,6 +528,9 @@ static void hsw_audio_codec_get_config(struct intel_encoder *encoder,
 
 	for (i = 0; i < len; i++)
 		eld[i] = intel_de_read(i915, HSW_AUD_EDID_DATA(cpu_transcoder));
+
+	if (hsw_hdac)
+		pm_runtime_put(&hsw_hdac->dev);
 }
 
 static void hsw_audio_codec_disable(struct intel_encoder *encoder,
@@ -520,6 +540,12 @@ static void hsw_audio_codec_disable(struct intel_encoder *encoder,
 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
 	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
 	enum transcoder cpu_transcoder = old_crtc_state->cpu_transcoder;
+	struct pci_dev *hsw_hdac;
+
+	/* on HSW/BDW ELD access doesn't work if the HDA controller is supended */
+	hsw_hdac = hsw_hda_controller(i915);
+	if (hsw_hdac)
+		pm_runtime_get_sync(&hsw_hdac->dev);
 
 	mutex_lock(&i915->display.audio.mutex);
 
@@ -544,6 +570,9 @@ static void hsw_audio_codec_disable(struct intel_encoder *encoder,
 		     AUDIO_OUTPUT_ENABLE(cpu_transcoder), 0);
 
 	mutex_unlock(&i915->display.audio.mutex);
+
+	if (hsw_hdac)
+		pm_runtime_put(&hsw_hdac->dev);
 }
 
 static unsigned int calc_hblank_early_prog(struct intel_encoder *encoder,
@@ -664,6 +693,12 @@ static void hsw_audio_codec_enable(struct intel_encoder *encoder,
 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
 	const u32 *eld = (const u32 *)crtc_state->eld;
 	int eld_buffer_size, len, i;
+	struct pci_dev *hsw_hdac;
+
+	/* on HSW/BDW ELD access doesn't work if the HDA controller is supended */
+	hsw_hdac = hsw_hda_controller(i915);
+	if (hsw_hdac)
+		pm_runtime_get_sync(&hsw_hdac->dev);
 
 	mutex_lock(&i915->display.audio.mutex);
 
@@ -705,6 +740,9 @@ static void hsw_audio_codec_enable(struct intel_encoder *encoder,
 	hsw_audio_config_update(encoder, crtc_state);
 
 	mutex_unlock(&i915->display.audio.mutex);
+
+	if (hsw_hdac)
+		pm_runtime_put(&hsw_hdac->dev);
 }
 
 struct ilk_audio_regs {
-- 
2.35.1