> -----Original Message-----
> From: Intel-gfx <[email protected]> On Behalf Of
> Kandpal, Suraj
> Sent: Monday, November 17, 2025 3:16 PM
> To: Manna, Animesh <[email protected]>; intel-
> [email protected]; [email protected]; dri-
> [email protected]
> Cc: Nikula, Jani <[email protected]>; Hogander, Jouni
> <[email protected]>
> Subject: RE: [PATCH v4 06/10] drm/i915/alpm: Half LFPS cycle calculation
>
> > Subject: [PATCH v4 06/10] drm/i915/alpm: Half LFPS cycle calculation
> >
> > Add support for half LFPS cycle calculation for DP2.1 ALPM as
> > dependent parameters got changed.
> >
> > v1: Initial version.
> > v2: Avoid returning early. [Jani]
> > v3: Use intel_crtc_has_type(). [Suraj]
> >
> > Cc: Jouni Högander <[email protected]>
> > Signed-off-by: Animesh Manna <[email protected]>
Also I did not find a correct place where this comment can be added hence
commenting it here
I think you have missed LFPS Cycle count calculation and modification to the
register bits
Have a look at that
Bspec: 71477
Regards,
Suraj Kandpal
> > ---
> > drivers/gpu/drm/i915/display/intel_alpm.c | 18 +++++++++++++-----
> > 1 file changed, 13 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> > b/drivers/gpu/drm/i915/display/intel_alpm.c
> > index 81472254ab73..33620f95ecc5 100644
> > --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> > +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> > @@ -73,12 +73,20 @@ static int get_silence_period_symbols(const struct
> > intel_crtc_state *crtc_state) 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;
> > + struct intel_display *display = to_intel_display(crtc_state);
> > +
> > + if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP)) {
> > + if (crtc_state->port_clock < 540000) {
> > + *min = DISPLAY_VER(display) < 35 ? 65 *
> > LFPS_CYCLE_COUNT : 140;
> > + *max = DISPLAY_VER(display) < 35 ? 75 *
> > LFPS_CYCLE_COUNT : 800;
> > + } else {
> > + *min = 140;
> > + *max = 800;
> > + }
> > } else {
> > - *min = 140;
> > - *max = 800;
> > + *min = 320;
> > + *max = 1600;
> > + return;
> > }
>
>
> This can be just
> struct intel_display *display = to_intel_display(crtc_state);
>
> *min = 140;
> *max= 180;
> if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP)) {
> if (crtc_state->port_clock < 540000 && DISPLAY_VER < 540000) {
> *min = 65 * LFPS_CYCLE_COUNT ;
> *max = 75 * LFPS_CYCLE_COUNT;
> } else {
> *min = 320;
> *max = 1600;
> return;
> }
>
> Regards,
> Suraj Kandpal
>
> >
> > --
> > 2.29.0
