Re: [PATCH v2 2/2] drm/i915: Add N & CTS values for 10/12 bit deep color

Jani Nikula
2019-05-15T14:36:48Z

On Tue, 02 Apr 2019, Aditya Swarup <aditya.swarup@intel.com> wrote:
> Adding N & CTS values for 10/12 bit deep color from Appendix C
> table in HDMI 2.0 spec. The correct values for N is not chosen
> automatically by hardware for deep color modes.
>
> v2: Remove redundant code and make it generic.(Jani)
>
> Signed-off-by: Aditya Swarup <aditya.swarup@intel.com>
> Cc: Clint Taylor <Clinton.A.Taylor@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Manasi Navare <manasi.d.navare@intel.com>
> ---
> drivers/gpu/drm/i915/intel_audio.c | 82 +++++++++++++++++++++++++-----
> 1 file changed, 69 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
> index 502b57ce72ab..ad53b04fa5a2 100644
> --- a/drivers/gpu/drm/i915/intel_audio.c
> +++ b/drivers/gpu/drm/i915/intel_audio.c
> @@ -70,6 +70,13 @@ struct dp_aud_n_m {
> u16 n;
> };
>
> +struct hdmi_aud_ncts_table {

The struct itself is not a table. Just make it struct hdmi_ncts or
something.

> + int sample_rate;
> + int clock;
> + int n;
> + int cts;
> +};
> +
> /* Values according to DP 1.4 Table 2-104 */
> static const struct dp_aud_n_m dp_aud_n_m[] = {
> { 32000, LC_162M, 1024, 10125 },
> @@ -146,12 +153,7 @@ static const struct {
> #define TMDS_594M 594000
> #define TMDS_593M 593407
>
> -static const struct {
> - int sample_rate;
> - int clock;
> - int n;
> - int cts;
> -} hdmi_aud_ncts[] = {
> +static const struct hdmi_aud_ncts_table hdmi_aud_ncts_24bpp[] = {
> { 32000, TMDS_296M, 5824, 421875 },
> { 32000, TMDS_297M, 3072, 222750 },
> { 32000, TMDS_593M, 5824, 843750 },
> @@ -182,6 +184,49 @@ static const struct {
> { 192000, TMDS_594M, 24576, 594000 },
> };
>
> +/* Appendix C - N & CTS values for deep color from HDMI 2.0 spec*/
> +/* HDMI N/CTS table for 10 bit deep color(30 bpp)*/
> +#define TMDS_371M 371250
> +#define TMDS_370M 370878
> +
> +static const struct hdmi_aud_ncts_table hdmi_aud_ncts_30bpp[] = {
> + { 32000, TMDS_370M, 5824, 527344 },

N should be 11648?

> + { 32000, TMDS_371M, 6144, 556875 },
> + { 44100, TMDS_370M, 8918, 585938 },

N 17836

> + { 44100, TMDS_371M, 4704, 309375 },
> + { 88200, TMDS_370M, 17836, 585938 },

N 35672

> + { 88200, TMDS_371M, 9408, 309375 },
> + { 176400, TMDS_370M, 35672, 585938 },

N 71344

> + { 176400, TMDS_371M, 18816, 309375 },
> + { 48000, TMDS_370M, 11648, 703125 },
> + { 48000, TMDS_371M, 5120, 309375 },
> + { 96000, TMDS_370M, 23296, 703125 },
> + { 96000, TMDS_371M, 10240, 309375 },
> + { 192000, TMDS_370M, 46592, 703125 },
> + { 192000, TMDS_371M, 20480, 309375 },
> +};
> +
> +/* HDMI N/CTS table for 12 bit deep color(36 bpp)*/
> +#define TMDS_445_5M 445500
> +#define TMDS_445M 445054
> +
> +static const struct hdmi_aud_ncts_table hdmi_aud_ncts_36bpp[] = {
> + { 32000, TMDS_445M, 5824, 632813 },
> + { 32000, TMDS_445_5M, 4096, 445500 },
> + { 44100, TMDS_445M, 8918, 703125 },
> + { 44100, TMDS_445_5M, 4704, 371250 },
> + { 88200, TMDS_445M, 17836, 703125 },
> + { 88200, TMDS_445_5M, 9408, 371250 },
> + { 176400, TMDS_445M, 35672, 703125 },
> + { 176400, TMDS_445_5M, 18816, 371250 },
> + { 48000, TMDS_445M, 5824, 421875 },
> + { 48000, TMDS_445_5M, 5120, 371250 },
> + { 96000, TMDS_445M, 11648, 421875 },
> + { 96000, TMDS_445_5M, 10240, 371250 },
> + { 192000, TMDS_445M, 23296, 421875 },
> + { 192000, TMDS_445_5M, 20480, 371250 },
> +};
> +
> /* get AUD_CONFIG_PIXEL_CLOCK_HDMI_* value for mode */
> static u32 audio_config_hdmi_pixel_clock(const struct intel_crtc_state *crtc_state)
> {
> @@ -210,16 +255,27 @@ static u32 audio_config_hdmi_pixel_clock(const struct intel_crtc_state *crtc_sta
> static int audio_config_hdmi_get_n(const struct intel_crtc_state *crtc_state,
> int rate)
> {
> - const struct drm_display_mode *adjusted_mode =
> - &crtc_state->base.adjusted_mode;
> - int i;
> + const struct hdmi_aud_ncts_table *hdmi_ncts_table;
> + int i, size = 0;

Unnecessary initialization.

> +
> + if (crtc_state->pipe_bpp == 36) {
> + hdmi_ncts_table = hdmi_aud_ncts_36bpp;
> + size = ARRAY_SIZE(hdmi_aud_ncts_36bpp);
> + } else if (crtc_state->pipe_bpp == 30) {
> + hdmi_ncts_table = hdmi_aud_ncts_30bpp;
> + size = ARRAY_SIZE(hdmi_aud_ncts_30bpp);
> + } else {
> + hdmi_ncts_table = hdmi_aud_ncts_24bpp;
> + size = ARRAY_SIZE(hdmi_aud_ncts_24bpp);
> + }
>
> - for (i = 0; i < ARRAY_SIZE(hdmi_aud_ncts); i++) {
> - if (rate == hdmi_aud_ncts[i].sample_rate &&
> - adjusted_mode->crtc_clock == hdmi_aud_ncts[i].clock) {
> - return hdmi_aud_ncts[i].n;
> + for (i = 0; i < size; i++) {
^
Superfluous space.

> + if (rate == hdmi_ncts_table[i].sample_rate &&
> + crtc_state->port_clock == hdmi_ncts_table[i].clock) {

Changing from adjusted_mode->crtc_clock to crtc_state->port_clock is a
separate change that needs to be a separate patch.

BR,
Jani.

> + return hdmi_ncts_table[i].n;
> }
> }
> +
> return 0;
> }

--
Jani Nikula, Intel Open Source Graphics Center