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) v2: Update the platform checks (Jani Nikula) Signed-off-by: Uma Shankar <uma.shankar@xxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_audio.c | 14 ++++++++++++++ drivers/gpu/drm/i915/display/intel_audio_regs.h | 3 +++ 2 files changed, 17 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c index 07e0c73204f3..61df5115c970 100644 --- a/drivers/gpu/drm/i915/display/intel_audio.c +++ b/drivers/gpu/drm/i915/display/intel_audio.c @@ -512,6 +512,13 @@ 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 + */ + if (DISPLAY_VER(i915) >= 20) + intel_de_rmw(i915, AUD_CHICKENBIT_REG3, CHICKEN3_SPARE18, 0); + mutex_unlock(&i915->display.audio.mutex); } @@ -637,6 +644,13 @@ 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 + */ + if (DISPLAY_VER(i915) >= 20) + 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
