On Tue, 25 Oct 2016, Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> wrote:
> Enabling DP audio stall fix is necessary to play audio over DP HBR2. So,
> let's set this bit right before enabling the audio codec. Playing audio
> without setting this bit results in pipe FIFO underruns.
>
> Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx>
The fix itself looks legit, but please move the enable to beginning of
hsw_audio_codec_enable and disable to end of hsw_audio_codec_disable in
intel_audio.c. Seems to me you don't have to have separate functions for
this, just add it inline there.
Is there a W/A name for this?
BR,
Jani.
> ---
> drivers/gpu/drm/i915/i915_reg.h | 5 +++++
> drivers/gpu/drm/i915/intel_ddi.c | 38 ++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_drv.h | 2 ++
> 3 files changed, 45 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 00efaa1..76dac48 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6236,6 +6236,11 @@ enum {
> #define SLICE_ECO_CHICKEN0 _MMIO(0x7308)
> #define PIXEL_MASK_CAMMING_DISABLE (1 << 14)
>
> +#define _CHICKEN_TRANS_A 0x420C0
> +#define _CHICKEN_TRANS_B 0x420C4
> +#define CHICKEN_TRANS(tran) _MMIO_TRANS(tran, _CHICKEN_TRANS_A, _CHICKEN_TRANS_B)
> +#define SPARE_13 (1<<13)
> +
> /* WaCatErrorRejectionIssue */
> #define GEN7_SQ_CHICKEN_MBCUNIT_CONFIG _MMIO(0x9030)
> #define GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB (1<<11)
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index fb18d69..84c91c1 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1858,6 +1858,38 @@ void intel_ddi_fdi_post_disable(struct intel_encoder *intel_encoder,
> I915_WRITE(FDI_RX_CTL(PIPE_A), val);
> }
>
> +void gen9_enable_dp_audio_stall_fix(struct intel_crtc_state *pipe_config)
> +{
> + struct drm_i915_private *dev_priv =
> + to_i915(pipe_config->base.crtc->dev);
> + enum transcoder cpu_transcoder = pipe_config->cpu_transcoder;
> + uint32_t temp;
> +
> + if (intel_crtc_has_dp_encoder(pipe_config) &&
> + pipe_config->port_clock >= 54000) {
> +
> + temp = I915_READ(CHICKEN_TRANS(cpu_transcoder));
> + temp |= SPARE_13;
> + I915_WRITE(CHICKEN_TRANS(cpu_transcoder), temp);
> + }
> +}
> +
> +void gen9_disable_dp_audio_stall_fix(struct intel_crtc_state *pipe_config)
> +{
> + struct drm_i915_private *dev_priv =
> + to_i915(pipe_config->base.crtc->dev);
> + enum transcoder cpu_transcoder = pipe_config->cpu_transcoder;
> + uint32_t temp;
> +
> + if (intel_crtc_has_dp_encoder(pipe_config) &&
> + pipe_config->port_clock >= 54000) {
> +
> + temp = I915_READ(CHICKEN_TRANS(cpu_transcoder));
> + temp &= ~SPARE_13;
> + I915_WRITE(CHICKEN_TRANS(cpu_transcoder), temp);
> + }
> +}
> +
> static void intel_enable_ddi(struct intel_encoder *intel_encoder,
> struct intel_crtc_state *pipe_config,
> struct drm_connector_state *conn_state)
> @@ -1893,6 +1925,9 @@ static void intel_enable_ddi(struct intel_encoder *intel_encoder,
> }
>
> if (intel_crtc->config->has_audio) {
> + if (IS_GEN9(dev_priv))
> + gen9_enable_dp_audio_stall_fix(pipe_config);
> +
> intel_display_power_get(dev_priv, POWER_DOMAIN_AUDIO);
> intel_audio_codec_enable(intel_encoder);
> }
> @@ -1912,6 +1947,9 @@ static void intel_disable_ddi(struct intel_encoder *intel_encoder,
> if (intel_crtc->config->has_audio) {
> intel_audio_codec_disable(intel_encoder);
> intel_display_power_put(dev_priv, POWER_DOMAIN_AUDIO);
> +
> + if (IS_GEN9(dev_priv))
> + gen9_disable_dp_audio_stall_fix(old_crtc_state);
> }
>
> if (type == INTEL_OUTPUT_EDP) {
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 4e90b07..ef02c62 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1189,6 +1189,8 @@ unsigned int intel_fb_align_height(struct drm_device *dev,
> uint64_t fb_format_modifier);
> u32 intel_fb_stride_alignment(const struct drm_i915_private *dev_priv,
> uint64_t fb_modifier, uint32_t pixel_format);
> +void gen9_enable_dp_audio_stall_fix(struct intel_crtc_state *pipe_config);
> +void gen9_disable_dp_audio_stall_fix(struct intel_crtc_state *pipe_config);
>
> /* intel_audio.c */
> void intel_init_audio_hooks(struct drm_i915_private *dev_priv);
--
Jani Nikula, Intel Open Source Technology Center
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