WA_14020863754: Corner case with Min Hblank Fix can cause
audio hang
Issue: Previously a fix was made to avoid issues with extremely
small hblanks, called the "Min Hblank Fix". However, this can
potentially cause an audio hang.
Workaround :
During "Audio Programming Sequence" Audio Enabling -
When DP mode is enabled Set mmio offset 0x65F1C bit 18 = 1b,
before step #1 "Enable audio Presence Detect"
During "Audio Programming Sequence" Audio Disabling -
When DP mode is enabled Clear mmio offset 0x65F1C bit 18 = 0b,
after step #6 "Disable Audio PD (Presence Detect)"
If not clearing PD bit, must also not clear 0x65F1C bit 18 (leave = 1b)
Signed-off-by: Uma Shankar <uma.shan...@intel.com>
---
drivers/gpu/drm/i915/display/intel_audio.c | 12 ++++++++++++
drivers/gpu/drm/i915/display/intel_audio_regs.h | 3 +++
2 files changed, 15 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_audio.c
b/drivers/gpu/drm/i915/display/intel_audio.c
index 07e0c73204f3..a8e3e515aaa0 100644
--- a/drivers/gpu/drm/i915/display/intel_audio.c
+++ b/drivers/gpu/drm/i915/display/intel_audio.c
@@ -512,6 +512,12 @@ static void hsw_audio_codec_disable(struct intel_encoder
*encoder,
intel_de_rmw(i915, HSW_AUD_PIN_ELD_CP_VLD,
AUDIO_OUTPUT_ENABLE(cpu_transcoder), 0);
+ /*
+ * WA_14020863754: Implement Audio Workaround
+ * Corner case with Min Hblank Fix can cause audio hang
+ */
+ intel_de_rmw(i915, AUD_CHICKENBIT_REG3, CHICKEN3_SPARE18, 0);
+
mutex_unlock(&i915->display.audio.mutex);
}
@@ -637,6 +643,12 @@ static void hsw_audio_codec_enable(struct intel_encoder
*encoder,
if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP))
enable_audio_dsc_wa(encoder, crtc_state);
+ /*
+ * WA_14020863754: Implement Audio Workaround
+ * Corner case with Min Hblank Fix can cause audio hang
+ */
+ intel_de_rmw(i915, AUD_CHICKENBIT_REG3, 0, CHICKEN3_SPARE18);
+
/* Enable audio presence detect */
intel_de_rmw(i915, HSW_AUD_PIN_ELD_CP_VLD,
0, AUDIO_OUTPUT_ENABLE(cpu_transcoder));
diff --git a/drivers/gpu/drm/i915/display/intel_audio_regs.h
b/drivers/gpu/drm/i915/display/intel_audio_regs.h
index 616e7b1275c4..6f8d33299ecd 100644
--- a/drivers/gpu/drm/i915/display/intel_audio_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_audio_regs.h
@@ -148,4 +148,7 @@
#define HBLANK_START_COUNT_96 4
#define HBLANK_START_COUNT_128 5
+#define AUD_CHICKENBIT_REG3 _MMIO(0x65F1C)
+#define CHICKEN3_SPARE18 REG_BIT(18)
+
#endif /* __INTEL_AUDIO_REGS_H__ */
--
2.42.0
