[alsa-devel] [PATCH] drm/i915: set proper N/CTS in modeset
Jani Nikula
jani.nikula at linux.intel.com
Wed Sep 16 15:03:15 CEST 2015
On Fri, 11 Sep 2015, libin.yang at intel.com wrote:
> From: Libin Yang <libin.yang at intel.com>
>
> When modeset occurs and the TMDS frequency is set to some
> speical values, the N/CTS need to be set manually if audio
> is playing.
>
> Signed-off-by: Libin Yang <libin.yang at intel.com>
> ---
> drivers/gpu/drm/i915/intel_audio.c | 56 ++++++++++++++++++++++++++++++++------
> include/drm/i915_component.h | 10 +++++++
> 2 files changed, 57 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
> index e3c32ce..a12bf57 100644
> --- a/drivers/gpu/drm/i915/intel_audio.c
> +++ b/drivers/gpu/drm/i915/intel_audio.c
> @@ -128,6 +128,20 @@ static int audio_config_get_n(const struct drm_display_mode *mode, int rate)
> return 0;
> }
>
> +static uint32_t audio_config_setup_n_reg(int n, uint32_t val)
> +{
> + int n_low, n_up;
> + uint32_t tmp = val;
> +
> + n_low = n & 0xfff;
> + n_up = (n >> 12) & 0xff;
> + tmp &= ~(AUD_CONFIG_UPPER_N_MASK | AUD_CONFIG_LOWER_N_MASK);
> + tmp |= ((n_up << AUD_CONFIG_UPPER_N_SHIFT) |
> + (n_low << AUD_CONFIG_LOWER_N_SHIFT) |
> + AUD_CONFIG_N_PROG_ENABLE);
> + return tmp;
> +}
> +
> /* check whether N/CTS/M need be set manually */
> static bool audio_rate_need_prog(struct intel_crtc *crtc,
> struct drm_display_mode *mode)
> @@ -262,9 +276,14 @@ static void hsw_audio_codec_enable(struct drm_connector *connector,
> struct drm_i915_private *dev_priv = connector->dev->dev_private;
> struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
> enum pipe pipe = intel_crtc->pipe;
> + struct i915_audio_component *acomp = dev_priv->audio_component;
> const uint8_t *eld = connector->eld;
> + struct intel_digital_port *intel_dig_port =
> + enc_to_dig_port(&encoder->base);
> + enum port port = intel_dig_port->port;
> uint32_t tmp;
> int len, i;
> + int n, rate;
>
> DRM_DEBUG_KMS("Enable audio codec on pipe %c, %u bytes ELD\n",
> pipe_name(pipe), drm_eld_size(eld));
> @@ -302,12 +321,29 @@ static void hsw_audio_codec_enable(struct drm_connector *connector,
> /* Enable timestamps */
> tmp = I915_READ(HSW_AUD_CFG(pipe));
> tmp &= ~AUD_CONFIG_N_VALUE_INDEX;
> - tmp &= ~AUD_CONFIG_N_PROG_ENABLE;
> tmp &= ~AUD_CONFIG_PIXEL_CLOCK_HDMI_MASK;
> if (intel_pipe_has_type(intel_crtc, INTEL_OUTPUT_DISPLAYPORT))
> tmp |= AUD_CONFIG_N_VALUE_INDEX;
> else
> tmp |= audio_config_hdmi_pixel_clock(mode);
> +
> + tmp &= ~AUD_CONFIG_N_PROG_ENABLE;
> + if (audio_rate_need_prog(intel_crtc, mode)) {
> + if (!acomp)
> + rate = 0;
> + else if (port >= PORT_A && port <= PORT_E)
> + rate = acomp->aud_sample_rate[port];
> + else {
> + DRM_ERROR("invalid port: %d\n", port);
> + rate = 0;
> + }
> + n = audio_config_get_n(mode, rate);
> + if (n != 0)
> + tmp = audio_config_setup_n_reg(n, tmp);
> + else
> + DRM_DEBUG_KMS("no suitable N value is found\n");
> + }
> +
> I915_WRITE(HSW_AUD_CFG(pipe), tmp);
>
> mutex_unlock(&dev_priv->av_mutex);
> @@ -594,9 +630,10 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
> struct intel_digital_port *intel_dig_port;
> struct intel_crtc *crtc;
> struct drm_display_mode *mode;
> + struct i915_audio_component *acomp = dev_priv->audio_component;
> enum pipe pipe = -1;
> u32 tmp;
> - int n_low, n_up, n;
> + int n;
>
> /* HSW, BDW SKL need this fix */
> if (!IS_SKYLAKE(dev_priv) &&
> @@ -630,6 +667,9 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
> pipe_name(pipe), port_name(port));
> mode = &crtc->config->base.adjusted_mode;
>
> + /* port must be valid now, otherwise the pipe will be invalid */
> + acomp->aud_sample_rate[port] = rate;
> +
> /* 2. check whether to set the N/CTS/M manually or not */
> if (!audio_rate_need_prog(crtc, mode)) {
> tmp = I915_READ(HSW_AUD_CFG(pipe));
> @@ -649,15 +689,10 @@ static int i915_audio_component_sync_audio_rate(struct device *dev,
> mutex_unlock(&dev_priv->av_mutex);
> return 0;
> }
> - n_low = n & 0xfff;
> - n_up = (n >> 12) & 0xff;
>
> - /* 4. set the N/CTS/M */
> + /* 3. set the N/CTS/M */
> tmp = I915_READ(HSW_AUD_CFG(pipe));
> - tmp &= ~(AUD_CONFIG_UPPER_N_MASK | AUD_CONFIG_LOWER_N_MASK);
> - tmp |= ((n_up << AUD_CONFIG_UPPER_N_SHIFT) |
> - (n_low << AUD_CONFIG_LOWER_N_SHIFT) |
> - AUD_CONFIG_N_PROG_ENABLE);
> + tmp = audio_config_setup_n_reg(n, tmp);
> I915_WRITE(HSW_AUD_CFG(pipe), tmp);
>
> mutex_unlock(&dev_priv->av_mutex);
> @@ -678,6 +713,7 @@ static int i915_audio_component_bind(struct device *i915_dev,
> {
> struct i915_audio_component *acomp = data;
> struct drm_i915_private *dev_priv = dev_to_i915(i915_dev);
> + int i;
>
> if (WARN_ON(acomp->ops || acomp->dev))
> return -EEXIST;
> @@ -685,6 +721,8 @@ static int i915_audio_component_bind(struct device *i915_dev,
> drm_modeset_lock_all(dev_priv->dev);
> acomp->ops = &i915_audio_component_ops;
> acomp->dev = i915_dev;
> + for (i = 0; i < I915_MAX_PORTS; i++)
> + acomp->aud_sample_rate[i] = 0;
> dev_priv->audio_component = acomp;
> drm_modeset_unlock_all(dev_priv->dev);
>
> diff --git a/include/drm/i915_component.h b/include/drm/i915_component.h
> index e6d35d7..89dc7d6 100644
> --- a/include/drm/i915_component.h
> +++ b/include/drm/i915_component.h
> @@ -24,8 +24,18 @@
> #ifndef _I915_COMPONENT_H_
> #define _I915_COMPONENT_H_
>
> +/* MAX_PORT is the number of port
> + * It must be sync with I915_MAX_PORTS defined i915_drv.h
> + * 5 should be enough as only HSW, BDW, SKL need such fix.
You should probably add BUILD_BUG_ON(MAX_PORTS != I915_MAX_PORTS)
somewhere near the loop above. Or at least change I915_MAX_PORTS to
ARRAY_SIZE(acomp->aud_sample_rate) in the loop to not run over the array
if MAX_PORTS gets out of sync.
With that addressed one way or another, this is
Reviewed-by: Jani Nikula <jani.nikula at intel.com>
> + */
> +#define MAX_PORTS 5
> +
> struct i915_audio_component {
> struct device *dev;
> + /**
> + * @aud_sample_rate: the array of audio sample rate per port
> + */
> + int aud_sample_rate[MAX_PORTS];
>
> const struct i915_audio_component_ops {
> struct module *owner;
> --
> 1.9.1
>
--
Jani Nikula, Intel Open Source Technology Center
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