[Intel-gfx] [PATCH v6 3/4] drm/i915: Haswell HDMI audio initialization

[Imre Deak]

Hi,

couple of comments inlined:

On Thu, Aug 9, 2012 at 11:52 AM, Wang Xingchao <xingchao.wang at intel.com> wrote:
> Added new haswell_write_eld() to initialize Haswell HDMI audio registers
> to generate an unsolicited response to the audio controller driver to
> indicate that the controller sequence should start.
>
> Signed-off-by: Wang Xingchao <xingchao.wang at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h      |    1 +
>  drivers/gpu/drm/i915/intel_display.c |   94 +++++++++++++++++++++++++++++++++-
>  2 files changed, 94 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 55aa10e..08f8b65 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4294,6 +4294,7 @@
>  #define   AUD_DIG_CNVT(pipe) _PIPE(pipe, \
>                                         HSW_AUD_DIG_CNVT_1, \
>                                         HSW_AUD_DIG_CNVT_2)
> +#define   DIP_PORT_SEL_MASK            0x3
>
>  #define   HSW_AUD_EDID_DATA_A          0x65050
>  #define   HSW_AUD_EDID_DATA_B          0x65150
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 70d30fc..be0950d 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -5067,6 +5067,98 @@ static void g4x_write_eld(struct drm_connector *connector,
>         I915_WRITE(G4X_AUD_CNTL_ST, i);
>  }
>
> +static void haswell_write_eld(struct drm_connector *connector,
> +                                    struct drm_crtc *crtc)
> +{
> +       struct drm_i915_private *dev_priv = connector->dev->dev_private;
> +       uint8_t *eld = connector->eld;
> +       uint32_t eldv;
> +       uint32_t i;
> +       int len;
> +       int pipe = to_intel_crtc(crtc)->pipe;
> +       int tmp;
> +
> +       int hdmiw_hdmiedid = HSW_AUD_EDID_DATA(pipe);
> +       int aud_cntl_st = HSW_AUD_DIP_ELD_CTRL(pipe);
> +       int aud_config = HSW_AUD_CFG(pipe);
> +       int aud_cntrl_st2 = HSW_AUD_PIN_ELD_CP_VLD;
> +
> +
> +       DRM_DEBUG_DRIVER("HDMI: Haswell Audio initialize....\n");
> +
> +       /* Audio output enable */
> +       DRM_DEBUG_DRIVER("HDMI audio: enable codec\n");
> +       tmp = I915_READ(aud_cntrl_st2);

uint32_t for tmp would be better, in case you happen to right shift
tmp with bit31 set.

> +       tmp |= (AUDIO_OUTPUT_ENABLE_A | AUDIO_OUTPUT_ENABLE_B | AUDIO_OUTPUT_ENABLE_C);
> +       I915_WRITE(aud_cntrl_st2, tmp);

I don't know much about HDMI, but according to the spec you'd need to
wait for one vblank here. At least a comment why we don't do it would
be nice.

> +
> +       /* Set ELD valid state */
> +       tmp = I915_READ(aud_cntrl_st2);
> +       DRM_DEBUG_DRIVER("HDMI audio: pin eld vld status=0x%8x\n", tmp);
> +       tmp |= (AUDIO_ELD_VALID_A | AUDIO_ELD_VALID_B | AUDIO_ELD_VALID_C);
> +       I915_WRITE(aud_cntrl_st2, tmp);
> +       tmp = I915_READ(aud_cntrl_st2);
> +       DRM_DEBUG_DRIVER("HDMI audio: eld vld status=0x%8x\n", tmp);
> +
> +       /* Enable HDMI mode */
> +       tmp = I915_READ(aud_config);
> +       DRM_DEBUG_DRIVER("HDMI audio: audio conf: 0x%8x\n", tmp);
> +       /* clear N_programing_enable and N_value_index */
> +       tmp &= ~(AUD_CONFIG_N_VALUE_INDEX | AUD_CONFIG_N_PROG_ENABLE);
> +       I915_WRITE(aud_config, tmp);
> +
> +       DRM_DEBUG_DRIVER("ELD on pipe %c\n", pipe_name(pipe));
> +
> +       i = I915_READ(aud_cntl_st);
> +       i = (i >> 29) & DIP_PORT_SEL_MASK;              /* DIP_Port_Select, 0x1 = PortB */
> +       if (!i) {
> +               DRM_DEBUG_DRIVER("Audio directed to unknown port\n");
> +               /* operate blindly on all ports */
> +               eldv = AUDIO_ELD_VALID_A;
> +               eldv |= AUDIO_ELD_VALID_B;
> +               eldv |= AUDIO_ELD_VALID_C;
> +       } else {
> +               DRM_DEBUG_DRIVER("ELD on port %c\n", 'A' + i);
> +               eldv = AUDIO_ELD_VALID_A << ((i - 1) * 4);

This is confusing. Reading the spec I undersand i=1 means port B, but
in that case we'll set eldv to AUDIO_ELD_VALID_A. Is it intentional?

Other than the above, for the patchset:

Reviewed-by: imre.deak at intel.com