[PATCH 2/2] drm/i915/display: Avoid use of VTOTAL.Vtotal bits
Ville Syrjälä
ville.syrjala at linux.intel.com
Wed Mar 26 13:35:10 UTC 2025
On Wed, Mar 26, 2025 at 09:35:38AM +0530, Ankit Nautiyal wrote:
> For platforms that always use VRR Timing Generator, the VTOTAL.Vtotal
> bits are not required. Since the support for these bits is going to
> be deprecated in upcoming platforms, avoid writing these bits for the
> platforms that do not use legacy Timing Generator.
>
> Since for these platforms TRAN_VMIN is always filled with crtc_vtotal,
> use TRAN_VRR_VMIN to get the vtotal for adjusted_mode.
>
> v2: Avoid having a helper for manipulating VTOTAL register, and instead
> just make the change where required. (Ville)
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 41 ++++++++++++++++++--
> drivers/gpu/drm/i915/display/intel_vrr.c | 15 +++++--
> 2 files changed, 50 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index bde53b2de70c..37e27dcfda05 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -2639,6 +2639,7 @@ static void intel_set_transcoder_timings(const struct intel_crtc_state *crtc_sta
> enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
> u32 crtc_vdisplay, crtc_vtotal, crtc_vblank_start, crtc_vblank_end;
> + u32 vtotal_bits;
> int vsyncshift = 0;
>
> drm_WARN_ON(display->drm, !transcoder_has_vrr(cpu_transcoder));
> @@ -2695,9 +2696,21 @@ static void intel_set_transcoder_timings(const struct intel_crtc_state *crtc_sta
> HSYNC_START(adjusted_mode->crtc_hsync_start - 1) |
> HSYNC_END(adjusted_mode->crtc_hsync_end - 1));
>
> + /*
> + * For platforms that always use VRR Timing Generator, the VTOTAL.Vtotal
> + * bits are not required. Since the support for these bits is going to
> + * be deprecated in upcoming platforms, avoid writing these bits for the
> + * platforms that do not use legacy Timing Generator.
> + */
> + if (intel_vrr_always_use_vrr_tg(display))
> + vtotal_bits = 0;
I think just setting crtc_vtotal=1 here (like we do for crtc_vblank_start)
would take care of this without the need for extra variables.
> + else
> + vtotal_bits = VTOTAL(crtc_vtotal - 1);
> +
> intel_de_write(display, TRANS_VTOTAL(display, cpu_transcoder),
> VACTIVE(crtc_vdisplay - 1) |
> - VTOTAL(crtc_vtotal - 1));
> + vtotal_bits);
> +
> intel_de_write(display, TRANS_VBLANK(display, cpu_transcoder),
> VBLANK_START(crtc_vblank_start - 1) |
> VBLANK_END(crtc_vblank_end - 1));
> @@ -2722,6 +2735,7 @@ static void intel_set_transcoder_timings_lrr(const struct intel_crtc_state *crtc
> enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
> u32 crtc_vdisplay, crtc_vtotal, crtc_vblank_start, crtc_vblank_end;
> + u32 vtotal_bits;
>
> drm_WARN_ON(display->drm, !transcoder_has_vrr(cpu_transcoder));
>
> @@ -2755,13 +2769,24 @@ static void intel_set_transcoder_timings_lrr(const struct intel_crtc_state *crtc
> intel_de_write(display, TRANS_VBLANK(display, cpu_transcoder),
> VBLANK_START(crtc_vblank_start - 1) |
> VBLANK_END(crtc_vblank_end - 1));
> + /*
> + * For platforms that always use VRR Timing Generator, the VTOTAL.Vtotal
> + * bits are not required. Since the support for these bits is going to
> + * be deprecated in upcoming platforms, avoid writing these bits for the
> + * platforms that do not use legacy Timing Generator.
> + */
> + if (intel_vrr_always_use_vrr_tg(display))
> + vtotal_bits = 0;
> + else
> + vtotal_bits = VTOTAL(crtc_vtotal - 1);
> +
> /*
> * The double buffer latch point for TRANS_VTOTAL
> * is the transcoder's undelayed vblank.
> */
> intel_de_write(display, TRANS_VTOTAL(display, cpu_transcoder),
> VACTIVE(crtc_vdisplay - 1) |
> - VTOTAL(crtc_vtotal - 1));
> + vtotal_bits);
>
> intel_vrr_set_fixed_rr_timings(crtc_state);
> intel_vrr_transcoder_enable(crtc_state);
> @@ -2824,7 +2849,17 @@ static void intel_get_transcoder_timings(struct intel_crtc *crtc,
>
> tmp = intel_de_read(display, TRANS_VTOTAL(display, cpu_transcoder));
> adjusted_mode->crtc_vdisplay = REG_FIELD_GET(VACTIVE_MASK, tmp) + 1;
> - adjusted_mode->crtc_vtotal = REG_FIELD_GET(VTOTAL_MASK, tmp) + 1;
> +
> + /*
> + * For platforms that always use VRR Timing Generator, the VTOTAL.Vtotal
> + * bits are not filled. The value for adjusted_mode->crtc_vtotal is read
> + * from VRR_VMIN register in intel_vrr_get_config.
> + * Just set this to 0 here.
> + */
> + if (intel_vrr_always_use_vrr_tg(display))
> + adjusted_mode->crtc_vtotal = 0;
> + else
> + adjusted_mode->crtc_vtotal = REG_FIELD_GET(VTOTAL_MASK, tmp) + 1;
>
> /* FIXME TGL+ DSI transcoders have this! */
> if (!transcoder_is_dsi(cpu_transcoder)) {
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index 414f93851059..cace1d7c99d5 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -674,9 +674,19 @@ void intel_vrr_get_config(struct intel_crtc_state *crtc_state)
> {
> struct intel_display *display = to_intel_display(crtc_state);
> enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> - u32 trans_vrr_ctl, trans_vrr_vsync;
> + u32 trans_vrr_ctl, trans_vrr_vsync, trans_vrr_vmin;
> bool vrr_enable;
>
> + /*
> + * For platforms that always use VRR Timing Generator, the VTOTAL.Vtotal
> + * bits are not filled. Since for these platforms TRAN_VMIN is always
> + * filled with crtc_vtotal, use TRAN_VRR_VMIN to get the vtotal for
> + * adjusted_mode.
> + */
> + trans_vrr_vmin = intel_de_read(display, TRANS_VRR_VMIN(display, cpu_transcoder)) + 1;
> + if (intel_vrr_always_use_vrr_tg(display))
> + crtc_state->hw.adjusted_mode.crtc_vtotal = trans_vrr_vmin;
I think this should rather use intel_vrr_vmin_vtotal(), and for
reason it needs to be near the end so thaI guess for that
reason it has to be done after the actual vmin readout.
> +
> trans_vrr_ctl = intel_de_read(display,
> TRANS_VRR_CTL(display, cpu_transcoder));
>
> @@ -705,8 +715,7 @@ void intel_vrr_get_config(struct intel_crtc_state *crtc_state)
> TRANS_VRR_FLIPLINE(display, cpu_transcoder)) + 1;
> crtc_state->vrr.vmax = intel_de_read(display,
> TRANS_VRR_VMAX(display, cpu_transcoder)) + 1;
> - crtc_state->vrr.vmin = intel_de_read(display,
> - TRANS_VRR_VMIN(display, cpu_transcoder)) + 1;
> + crtc_state->vrr.vmin = trans_vrr_vmin;
>
> if (HAS_AS_SDP(display)) {
> trans_vrr_vsync =
> --
> 2.45.2
--
Ville Syrjälä
Intel
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