> -----Original Message-----
> From: Intel-gfx [mailto:intel-gfx-boun...@lists.freedesktop.org] On Behalf Of
> Lin, Mengdong
> Sent: Wednesday, October 12, 2016 10:46 AM
> To: Nikula, Jani <jani.nik...@intel.com>; intel-gfx@lists.freedesktop.org
> Cc: Nikula, Jani <jani.nik...@intel.com>; libin.y...@linux.intel.com;
> Pandiyan, Dhinakaran <dhinakaran.pandi...@intel.com>
> Subject: Re: [Intel-gfx] [PATCH RESEND 9/9] drm/i915: set proper N/M in
> modeset
>
>
>
> > -----Original Message-----
> > From: Intel-gfx [mailto:intel-gfx-boun...@lists.freedesktop.org] On
> > Behalf Of Jani Nikula
> > Sent: Monday, October 10, 2016 11:04 PM
> > To: intel-gfx@lists.freedesktop.org
> > Cc: Nikula, Jani <jani.nik...@intel.com>; libin.y...@linux.intel.com;
> > Pandiyan, Dhinakaran <dhinakaran.pandi...@intel.com>
> > Subject: [Intel-gfx] [PATCH RESEND 9/9] drm/i915: set proper N/M in
> > modeset
> >
> > When modeset occurs and the LS_CLK is set to some special values in DP
> > mode, the N/M need to be set manually if audio is playing. Otherwise
> > the first several seconds may be silent in audio playback.
> >
> > The relationship of Maud and Naud is expressed in the following equation:
> > Maud/Naud = 512 * fs / f_LS_Clk
> >
> > Please refer VESA DisplayPort Standard spec for details.
> >
> > Signed-off-by: Libin Yang <libin.y...@linux.intel.com>
> > Signed-off-by: Jani Nikula <jani.nik...@intel.com>
> > ---
> > drivers/gpu/drm/i915/i915_reg.h | 7 +++
> > drivers/gpu/drm/i915/intel_audio.c | 100
> > ++++++++++++++++++++++++++++++++++++-
> > 2 files changed, 105 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h index 595d196f753f..8d9dbc7d5b32
> > 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -7359,6 +7359,13 @@ enum {
> > #define _HSW_AUD_MISC_CTRL_B 0x65110
> > #define HSW_AUD_MISC_CTRL(pipe) _MMIO_PIPE(pipe,
> > _HSW_AUD_MISC_CTRL_A, _HSW_AUD_MISC_CTRL_B)
> >
> > +#define _HSW_AUD_M_CTS_ENABLE_A 0x65028
> > +#define _HSW_AUD_M_CTS_ENABLE_B 0x65128
> > +#define HSW_AUD_M_CTS_ENABLE(pipe) _MMIO_PIPE(pipe,
> > _HSW_AUD_M_CTS_ENABLE_A, _HSW_AUD_M_CTS_ENABLE_B)
> > +#define AUD_M_CTS_M_VALUE_INDEX (1 << 21)
> > +#define AUD_M_CTS_M_PROG_ENABLE (1 << 20)
> > +#define AUD_CONFIG_M_MASK 0xfffff
>
> The last line cause misalignment after applying the patch.
>
> > +
> > #define _HSW_AUD_DIP_ELD_CTRL_ST_A 0x650b4
> > #define _HSW_AUD_DIP_ELD_CTRL_ST_B 0x651b4
> > #define HSW_AUD_DIP_ELD_CTRL(pipe) _MMIO_PIPE(pipe,
> > _HSW_AUD_DIP_ELD_CTRL_ST_A, _HSW_AUD_DIP_ELD_CTRL_ST_B) diff --
> git
> > a/drivers/gpu/drm/i915/intel_audio.c
> > b/drivers/gpu/drm/i915/intel_audio.c
> > index 81df29ca4947..0bc2701b6c9c 100644
> > --- a/drivers/gpu/drm/i915/intel_audio.c
> > +++ b/drivers/gpu/drm/i915/intel_audio.c
> > @@ -57,6 +57,70 @@
> > * struct &i915_audio_component_audio_ops @audio_ops is called from
> > i915 driver.
> > */
> >
> > +/* DP N/M table */
> > +#define LC_540M 540000
> > +#define LC_270M 270000
> > +#define LC_162M 162000
> > +
> > +struct dp_aud_n_m {
> > + int sample_rate;
> > + int clock;
> > + u16 n;
> > + u16 m;
> > +};
> > +
> > +static const struct dp_aud_n_m dp_aud_n_m[] = {
> > + { 192000, LC_540M, 5625, 1024 },
> > + { 176400, LC_540M, 9375, 1568 },
> > + { 96000, LC_540M, 5625, 512 },
> > + { 88200, LC_540M, 9375, 784 },
> > + { 48000, LC_540M, 5625, 256 },
> > + { 44100, LC_540M, 9375, 392 },
> > + { 32000, LC_540M, 16875, 512 },
> > + { 192000, LC_270M, 5625, 2048 },
> > + { 176400, LC_270M, 9375, 3136 },
> > + { 96000, LC_270M, 5625, 1024 },
> > + { 88200, LC_270M, 9375, 1568 },
> > + { 48000, LC_270M, 5625, 512 },
> > + { 44100, LC_270M, 9375, 784 },
> > + { 32000, LC_270M, 16875, 1024 },
> > + { 192000, LC_162M, 3375, 2048 },
> > + { 176400, LC_162M, 5625, 3136 },
> > + { 96000, LC_162M, 3375, 1024 },
> > + { 88200, LC_162M, 5625, 1568 },
> > + { 48000, LC_162M, 3375, 512 },
> > + { 44100, LC_162M, 5625, 784 },
> > + { 32000, LC_162M, 10125, 1024 },
> > +};
> > +
> > +static const struct dp_aud_n_m *
> > +audio_config_dp_get_n_m(struct intel_crtc *intel_crtc, int rate) {
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(dp_aud_n_m); i++) {
> > + if (rate == dp_aud_n_m[i].sample_rate &&
> > + intel_crtc->config->port_clock == dp_aud_n_m[i].clock)
> > + return &dp_aud_n_m[i];
> > + }
> > +
> > + return NULL;
> > +}
> > +
> > +static int audio_config_dp_get_m(struct intel_crtc *intel_crtc, int
> > +rate) {
> > + const struct dp_aud_n_m *nm =
> > audio_config_dp_get_n_m(intel_crtc,
> > +rate);
> > +
> > + return nm ? nm->m : 0;
> > +}
> > +
> > +static int audio_config_dp_get_n(struct intel_crtc *intel_crtc, int
> > +rate) {
> > + const struct dp_aud_n_m *nm =
> > audio_config_dp_get_n_m(intel_crtc,
> > +rate);
> > +
> > + return nm ? nm->n : 0;
> > +}
> > +
> > static const struct {
> > int clock;
> > u32 config;
> > @@ -225,8 +289,10 @@ hsw_dp_audio_config_update(struct intel_crtc
> > *intel_crtc, enum port port,
> > const struct drm_display_mode *adjusted_mode) {
> > struct drm_i915_private *dev_priv = to_i915(intel_crtc->base.dev);
> > + struct i915_audio_component *acomp = dev_priv-
> > >audio_component;
> > + int rate = acomp ? acomp->aud_sample_rate[port] : 0;
> > enum pipe pipe = intel_crtc->pipe;
> > - u32 tmp;
> > + u32 tmp, n, m;
> >
> > tmp = I915_READ(HSW_AUD_CFG(pipe));
> > tmp &= ~AUD_CONFIG_N_VALUE_INDEX;
> > @@ -234,7 +300,30 @@ hsw_dp_audio_config_update(struct intel_crtc
> > *intel_crtc, enum port port,
> > tmp &= ~AUD_CONFIG_N_PROG_ENABLE;
> > tmp |= AUD_CONFIG_N_VALUE_INDEX;
> >
> > + if (intel_crtc->config->port_clock == LC_540M ||
> > + intel_crtc->config->port_clock == LC_270M ||
> > + intel_crtc->config->port_clock == LC_162M) {
> > + n = audio_config_dp_get_n(intel_crtc, rate);
> > + if (n != 0) {
> > + tmp &= ~AUD_CONFIG_N_MASK;
> > + tmp |= AUD_CONFIG_N(n);
> > + tmp |= AUD_CONFIG_N_PROG_ENABLE;
> > + } else {
> > + DRM_DEBUG_KMS("no suitable N value is found\n");
>
> Could some comments be added here why we don't return if no valid N value
> is found?
This is because although we don't need set N value here, but there are some
other bits to be set. So you can see we call
I915_WRITE(HSW_AUD_CFG(pipe), tmp);
Later.
> Do we still need to program write the register to let HW calculate N by
> itself?
Ideally, all the frequency should be in the table. But if the frequency is not
in our table, we will let HW calculate N by itself.
>
> > + }
> > + }
> > +
> > I915_WRITE(HSW_AUD_CFG(pipe), tmp);
>
> And if no valid N value is found, need we go ahead to check M value?
If there is no valid N value, audio_config_dp_get_m(intel_crtc, rate);
will also return 0 and skip the m setting.
Regards,
Libin
>
> > +
> > + m = audio_config_dp_get_m(intel_crtc, rate);
> > + if (m) {
> > + tmp = I915_READ(HSW_AUD_M_CTS_ENABLE(pipe));
> > + tmp &= ~AUD_CONFIG_M_MASK;
> > + tmp |= m;
> > + tmp |= AUD_M_CTS_M_VALUE_INDEX;
> > + tmp |= AUD_M_CTS_M_PROG_ENABLE;
> > + I915_WRITE(HSW_AUD_M_CTS_ENABLE(pipe), tmp);
> > + }
> > }
>
> Thanks
> Mengdong
>
> > static void
> > @@ -267,6 +356,12 @@ hsw_hdmi_audio_config_update(struct intel_crtc
> > *intel_crtc, enum port port,
> > }
> >
> > I915_WRITE(HSW_AUD_CFG(pipe), tmp);
> > +
> > + 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);
> > }
> >
> > static void
> > @@ -687,7 +782,8 @@ static int
> > i915_audio_component_sync_audio_rate(struct device *kdev, int port,
> > /* 1. get the pipe */
> > intel_encoder = get_saved_enc(dev_priv, port, pipe);
> > if (!intel_encoder || !intel_encoder->base.crtc ||
> > - intel_encoder->type != INTEL_OUTPUT_HDMI) {
> > + (intel_encoder->type != INTEL_OUTPUT_HDMI &&
> > + intel_encoder->type != INTEL_OUTPUT_DP)) {
> > DRM_DEBUG_KMS("Not valid for port %c\n",
> port_name(port));
> > err = -ENODEV;
> > goto unlock;
> > --
> > 2.1.4
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> _______________________________________________
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