> -----Original Message-----
> From: Intel-xe <intel-xe-boun...@lists.freedesktop.org> On Behalf Of Jouni
> Högander
> Sent: Friday, 12 September 2025 9.41
> To: intel...@lists.freedesktop.org; intel-gfx@lists.freedesktop.org
> Cc: Hogander, Jouni <jouni.hogan...@intel.com>
> Subject: [PATCH] drm/i915/alpm: Remove error handling from
> get_lfps_cycle_min_max_time
>
> Getter for LFPS cycle min/max times is unnecessarily checking faulty port
> clock value. This doesn't make sense as erroneous port
> clock value would have been noticed already at this point. Remove this check
> and use 140/800 ns always when port clock >
> 540000.
>
Reviewed-by: Mika Kahola <mika.kah...@intel.com>
> Signed-off-by: Jouni Högander <jouni.hogan...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_alpm.c | 29 +++++++----------------
> 1 file changed, 8 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> b/drivers/gpu/drm/i915/display/intel_alpm.c
> index ed7a7ed486b5..749119cc0b28 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> @@ -58,43 +58,32 @@ static int get_silence_period_symbols(const struct
> intel_crtc_state *crtc_state)
> 1000 / 1000;
> }
>
> -static int get_lfps_cycle_min_max_time(const struct intel_crtc_state
> *crtc_state,
> - int *min, int *max)
> +static void get_lfps_cycle_min_max_time(const struct intel_crtc_state
> *crtc_state,
> + int *min, int *max)
> {
> if (crtc_state->port_clock < 540000) {
> *min = 65 * LFPS_CYCLE_COUNT;
> *max = 75 * LFPS_CYCLE_COUNT;
> - } else if (crtc_state->port_clock <= 810000) {
> + } else {
> *min = 140;
> *max = 800;
> - } else {
> - *min = *max = -1;
> - return -1;
> }
> -
> - return 0;
> }
>
> static int get_lfps_cycle_time(const struct intel_crtc_state *crtc_state) {
> - int tlfps_cycle_min, tlfps_cycle_max, ret;
> + int tlfps_cycle_min, tlfps_cycle_max;
>
> - ret = get_lfps_cycle_min_max_time(crtc_state, &tlfps_cycle_min,
> - &tlfps_cycle_max);
> - if (ret)
> - return ret;
> + get_lfps_cycle_min_max_time(crtc_state, &tlfps_cycle_min,
> + &tlfps_cycle_max);
>
> return tlfps_cycle_min + (tlfps_cycle_max - tlfps_cycle_min) / 2; }
>
> static int get_lfps_half_cycle_clocks(const struct intel_crtc_state
> *crtc_state) {
> - int lfps_cycle_time = get_lfps_cycle_time(crtc_state);
> -
> - if (lfps_cycle_time < 0)
> - return -1;
> -
> - return lfps_cycle_time * crtc_state->port_clock / 1000 / 1000 / (2 *
> LFPS_CYCLE_COUNT);
> + return get_lfps_cycle_time(crtc_state) * crtc_state->port_clock / 1000 /
> + 1000 / (2 * LFPS_CYCLE_COUNT);
> }
>
> /*
> @@ -146,8 +135,6 @@ _lnl_compute_aux_less_alpm_params(struct intel_dp
> *intel_dp,
> silence_period = get_silence_period_symbols(crtc_state);
>
> lfps_half_cycle = get_lfps_half_cycle_clocks(crtc_state);
> - if (lfps_half_cycle < 0)
> - return false;
>
> if (aux_less_wake_lines > ALPM_CTL_AUX_LESS_WAKE_TIME_MASK ||
> silence_period > PORT_ALPM_CTL_SILENCE_PERIOD_MASK ||
> --
> 2.43.0
