Re: [PATCH v6 05/18] drm/i915/alpm: Refactor Auxless wake time calculation

["Hogander, Jouni" <jouni.hogander@intel.com>]

On Tue, 2026-09-15 at 23:34 +0530, Animesh Manna wrote:
> Divide the auxless wake time calculation in parts which will
> help later to add Xe3p related modification.
> 
> v2: Refactor first existing calculation. [Jani]
> v3: Cosmetic changes. [Jani, Suraj]
> 
> Bspec: 71477
> Cc: Jouni Högander <jouni.hogander@intel.com>
> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
> Signed-off-by: Animesh Manna <animesh.manna@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_alpm.c | 31 ++++++++++++++++-----
> --
>  1 file changed, 22 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> b/drivers/gpu/drm/i915/display/intel_alpm.c
> index 901493bb1448..d5823174576a 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> @@ -102,6 +102,25 @@ static int get_lfps_half_cycle_clocks(const
> struct intel_crtc_state *crtc_state)
>  		1000 / (2 * LFPS_CYCLE_COUNT);
>  }
>  
> +static int get_tphy2_p2_to_p0(const struct intel_crtc_state
> *crtc_state)
> +{
> +	return 12 * 1000;
> +}
> +
> +static int get_establishment_period(const struct intel_crtc_state
> *crtc_state)
> +{
> +	int t1 = 50 * 1000;
> +	int tps4 = 252;
> +	/* port_clock is link rate in 10kbit/s units */
> +	int tml_phy_lock = 1000 * 1000 * tps4 / crtc_state-
> >port_clock;
> +	int tcds, establishment_period;
> +
> +	tcds = (7 + DIV_ROUND_UP(6500, tml_phy_lock) + 1) *
> tml_phy_lock;
> +	establishment_period = (SILENCE_PERIOD_TIME + t1 + tcds);

Here you could return SILENCE_PERIOD_TIME + t1 + tcds.

> +
> +	return establishment_period;
> +}
> +
>  /*
>   * AUX-Less Wake Time = CEILING( ((PHY P2 to P0) + tLFPS_Period,
> Max+
>   * tSilence, Max+ tPHY Establishment + tCDS) / tline)
> @@ -123,17 +142,11 @@ static int get_lfps_half_cycle_clocks(const
> struct intel_crtc_state *crtc_state)
>   */
>  static int _lnl_compute_aux_less_wake_time(const struct
> intel_crtc_state *crtc_state)
>  {
> -	int tphy2_p2_to_p0 = 12 * 1000;
> -	int t1 = 50 * 1000;
> -	int tps4 = 252;
> -	/* port_clock is link rate in 10kbit/s units */
> -	int tml_phy_lock = 1000 * 1000 * tps4 / crtc_state-
> >port_clock;
> -	int num_ml_phy_lock = 7 + DIV_ROUND_UP(6500, tml_phy_lock) +
> 1;

I think you should keep num_ml_phy_lock also in your helper. Just to
keep readability. Also in patch 6 you will have then:

if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP)) {
	num_ml_phy_lock = 7 + DIV_ROUND_UP(6500, tml_phy_lock) + 1;
} else {
...
	num_ml_phy_lock = 7;
...

tcds = num_ml_phy_lock * tml_phy_lock;

BR,
Jouni Högander

> -	int t2 = num_ml_phy_lock * tml_phy_lock;
> -	int tcds = 1 * t2;
> +	int tphy2_p2_to_p0 = get_tphy2_p2_to_p0(crtc_state);
> +	int establishment_period =
> get_establishment_period(crtc_state);
>  
>  	return DIV_ROUND_UP(tphy2_p2_to_p0 +
> get_lfps_cycle_time(crtc_state) +
> -			    SILENCE_PERIOD_TIME + t1 + tcds, 1000);
> +			    establishment_period, 1000);
>  }
>  
>  static int