From: Libin Yang <libin.y...@intel.com>
This issue is caused by:
6014ac12: drm/i915/audio: set proper N/M in modeset
Some special monitors will have noise or even no sound after
applying the patch 6014ac12.
In patch 6014ac12, it will reset the cts value to 0 for HDMI.
However, we need disable Enable CTS or M Prog bit. This is
the initial setting after HW reset.
Signed-off-by: Libin Yang <libin.y...@intel.com>
---
drivers/gpu/drm/i915/intel_audio.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_audio.c
b/drivers/gpu/drm/i915/intel_audio.c
index 813fd74..a472d35 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -332,6 +332,13 @@ hsw_hdmi_audio_config_update(struct intel_crtc
*intel_crtc, enum port port,
int n;
u32 tmp;
+ /* reset CTS value to 0 */
+ tmp = I915_READ(HSW_AUD_M_CTS_ENABLE(pipe));
+ tmp &= ~AUD_CONFIG_M_MASK;
+ tmp &= ~AUD_M_CTS_M_VALUE_INDEX;
+ tmp |= AUD_M_CTS_M_PROG_ENABLE;
+ I915_WRITE(HSW_AUD_M_CTS_ENABLE(pipe), tmp);
+
tmp = I915_READ(HSW_AUD_CFG(pipe));
tmp &= ~AUD_CONFIG_N_VALUE_INDEX;
tmp &= ~AUD_CONFIG_PIXEL_CLOCK_HDMI_MASK;
@@ -351,10 +358,12 @@ hsw_hdmi_audio_config_update(struct intel_crtc
*intel_crtc, enum port port,
I915_WRITE(HSW_AUD_CFG(pipe), tmp);
+ /*
+ * Let's disable "Enable CTS or M Prog bit"
+ * and let HW calculate the value
+ */
tmp = I915_READ(HSW_AUD_M_CTS_ENABLE(pipe));
- tmp &= ~AUD_CONFIG_M_MASK;
- tmp &= ~AUD_M_CTS_M_VALUE_INDEX;
- tmp |= AUD_M_CTS_M_PROG_ENABLE;
+ tmp &= ~AUD_M_CTS_M_PROG_ENABLE;
I915_WRITE(HSW_AUD_M_CTS_ENABLE(pipe), tmp);
}
--
2.7.4
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
