Re: [Intel-gfx] [RFC 2/4] drm/i915/display: Add 480 MHz CDCLK steps for RPL-U

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 02 Jan 2023, Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com> wrote:
> A new step of 480MHz has been added on SKUs that have a RPL-U
> device id to support 120Hz displays more efficiently. Use a
> new quirk to identify the machine for which this change needs
> to be applied.

Again, it's not a quirk, and should not be added as one.

BR,
Jani.

>
> BSpec: 55409
>
> Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_cdclk.c | 25 ++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index 0c107a38f9d0..f5df0a806765 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -38,6 +38,7 @@
>  #include "intel_pcode.h"
>  #include "intel_psr.h"
>  #include "vlv_sideband.h"
> +#include "intel_quirks.h"
>  
>  /**
>   * DOC: CDCLK / RAWCLK
> @@ -1329,6 +1330,27 @@ static const struct intel_cdclk_vals adlp_cdclk_table[] = {
>  	{}
>  };
>  
> +static const struct intel_cdclk_vals rplu_cdclk_table[] = {
> +	{ .refclk = 19200, .cdclk = 172800, .divider = 3, .ratio = 27 },
> +	{ .refclk = 19200, .cdclk = 192000, .divider = 2, .ratio = 20 },
> +	{ .refclk = 19200, .cdclk = 480000, .divider = 2, .ratio = 50 },
> +	{ .refclk = 19200, .cdclk = 556800, .divider = 2, .ratio = 58 },
> +	{ .refclk = 19200, .cdclk = 652800, .divider = 2, .ratio = 68 },
> +
> +	{ .refclk = 24000, .cdclk = 176000, .divider = 3, .ratio = 22 },
> +	{ .refclk = 24000, .cdclk = 192000, .divider = 2, .ratio = 16 },
> +	{ .refclk = 24000, .cdclk = 480000, .divider = 2, .ratio = 40 },
> +	{ .refclk = 24000, .cdclk = 552000, .divider = 2, .ratio = 46 },
> +	{ .refclk = 24400, .cdclk = 648000, .divider = 2, .ratio = 54 },
> +
> +	{ .refclk = 38400, .cdclk = 179200, .divider = 3, .ratio = 14 },
> +	{ .refclk = 38400, .cdclk = 192000, .divider = 2, .ratio = 10 },
> +	{ .refclk = 38400, .cdclk = 480000, .divider = 2, .ratio = 25 },
> +	{ .refclk = 38400, .cdclk = 556800, .divider = 2, .ratio = 29 },
> +	{ .refclk = 38400, .cdclk = 652800, .divider = 2, .ratio = 34 },
> +	{}
> +};
> +
>  static const struct intel_cdclk_vals dg2_cdclk_table[] = {
>  	{ .refclk = 38400, .cdclk = 163200, .divider = 2, .ratio = 34, .waveform = 0x8888 },
>  	{ .refclk = 38400, .cdclk = 204000, .divider = 2, .ratio = 34, .waveform = 0x9248 },
> @@ -3353,6 +3375,9 @@ void intel_init_cdclk_hooks(struct drm_i915_private *dev_priv)
>  		/* Wa_22011320316:adl-p[a0] */
>  		if (IS_ADLP_DISPLAY_STEP(dev_priv, STEP_A0, STEP_B0))
>  			dev_priv->display.cdclk.table = adlp_a_step_cdclk_table;
> +		/* BSpec: 55409 */

We don't bother with bspec references in code. Add them in commit
messages.

> +		else if (intel_has_quirk(dev_priv, QUIRK_480MHZ_CDCLK_STEP))
> +			dev_priv->display.cdclk.table = rplu_cdclk_table;
>  		else
>  			dev_priv->display.cdclk.table = adlp_cdclk_table;
>  	} else if (IS_ROCKETLAKE(dev_priv)) {

-- 
Jani Nikula, Intel Open Source Graphics Center