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drm/i915: Implement Audio WA_14020863754

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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)

v3: Limited the WA to LNL and BMG, added a helper (Matt Roper)

v4: Updated the bit naming, fixed redundant if statement

Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240509053508.2807834-1-uma.shankar@intel.com
This commit is contained in:
Uma Shankar
2024-05-09 11:05:08 +05:30
parent 84ceb14076
commit 56c12ec72a
2 changed files with 18 additions and 0 deletions
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15
drivers/gpu/drm/i915/display/intel_audio.c
View File

@@ -183,6 +183,15 @@ static const struct hdmi_aud_ncts hdmi_aud_ncts_36bpp[] = {
{ 192000, TMDS_445_5M, 20480, 371250 },
};
/*
* WA_14020863754: Implement Audio Workaround
* Corner case with Min Hblank Fix can cause audio hang
*/
static bool needs_wa_14020863754(struct drm_i915_private *i915)
{
return (DISPLAY_VER(i915) == 20 || IS_BATTLEMAGE(i915));
}
/* get AUD_CONFIG_PIXEL_CLOCK_HDMI_* value for mode */
static u32 audio_config_hdmi_pixel_clock(const struct intel_crtc_state *crtc_state)
{
@@ -415,6 +424,9 @@ 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);
if (needs_wa_14020863754(i915))
intel_de_rmw(i915, AUD_CHICKENBIT_REG3, DACBE_DISABLE_MIN_HBLANK_FIX, 0);
mutex_unlock(&i915->display.audio.mutex);
}
@@ -540,6 +552,9 @@ 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);
if (needs_wa_14020863754(i915))
intel_de_rmw(i915, AUD_CHICKENBIT_REG3, 0, DACBE_DISABLE_MIN_HBLANK_FIX);
/* Enable audio presence detect */
intel_de_rmw(i915, HSW_AUD_PIN_ELD_CP_VLD,
0, AUDIO_OUTPUT_ENABLE(cpu_transcoder));

3
drivers/gpu/drm/i915/display/intel_audio_regs.h
View File

@@ -164,4 +164,7 @@
_VLV_AUD_PORT_EN_D_DBG)
#define VLV_AMP_MUTE (1 << 1)
#define AUD_CHICKENBIT_REG3 _MMIO(0x65F1C)
#define DACBE_DISABLE_MIN_HBLANK_FIX REG_BIT(18)
#endif /* __INTEL_AUDIO_REGS_H__ */