On Tue, Nov 28, 2023 at 10:37:53AM +0200, Stanislav Lisovskiy wrote:
> We need that in order to force disable SAGV in next patch.
> Also it is beneficial to separate that code, as in majority cases,
> when SAGV is enabled, we don't even need those calculations.
> Also we probably need to determine max PSF GV point as well, however
> currently we don't do that when we disable SAGV, which might be
> actually causing some issues in that case.
>
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_bw.c | 82 ++++++++++++++++++++-----
> 1 file changed, 65 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
> index 583cd2ebdf89..efd408e96e8a 100644
> --- a/drivers/gpu/drm/i915/display/intel_bw.c
> +++ b/drivers/gpu/drm/i915/display/intel_bw.c
> @@ -805,6 +805,64 @@ intel_atomic_get_bw_state(struct intel_atomic_state *state)
> return to_intel_bw_state(bw_state);
> }
>
> +static unsigned int icl_max_bw_qgv_point(struct drm_i915_private *i915,
> + int num_active_planes)
> +{
> + unsigned int max_bw_point = 0;
> + unsigned int max_bw = 0;
> + unsigned int num_qgv_points = i915->display.bw.max[0].num_qgv_points;
> + int i;
> +
> + for (i = 0; i < num_qgv_points; i++) {
> + unsigned int idx;
> + unsigned int max_data_rate;
> +
> + if (DISPLAY_VER(i915) > 11)
> + idx = tgl_max_bw_index(i915, num_active_planes, i);
> + else
> + idx = icl_max_bw_index(i915, num_active_planes, i);
> +
> + if (idx >= ARRAY_SIZE(i915->display.bw.max))
> + continue;
> +
> + max_data_rate = i915->display.bw.max[idx].deratedbw[i];
Looks like that that part could be extracted to a helper
to be used by both codepaths (would be a natural counterpart
to adl_psf_bw()).
> +
> + /*
> + * We need to know which qgv point gives us
> + * maximum bandwidth in order to disable SAGV
> + * if we find that we exceed SAGV block time
> + * with watermarks. By that moment we already
> + * have those, as it is calculated earlier in
> + * intel_atomic_check,
> + */
> + if (max_data_rate > max_bw) {
> + max_bw_point = i;
> + max_bw = max_data_rate;
> + }
> + }
> +
> + return max_bw_point;
> +}
> +
> +unsigned int icl_max_bw_psf_gv_point(struct drm_i915_private *i915)
> +{
> + unsigned int num_psf_gv_points = i915->display.bw.max[0].num_psf_gv_points;
> + unsigned int max_bw = 0;
> + unsigned int max_bw_point = 0;
> + int i;
> +
> + for (i = 0; i < num_psf_gv_points; i++) {
> + unsigned int max_data_rate = adl_psf_bw(i915, i);
> +
> + if (max_data_rate > max_bw) {
> + max_bw_point = i;
> + max_bw = max_data_rate;
> + }
> + }
> +
> + return max_bw_point;
> +}
> +
> static int mtl_find_qgv_points(struct drm_i915_private *i915,
> unsigned int data_rate,
> unsigned int num_active_planes,
> @@ -882,8 +940,6 @@ static int icl_find_qgv_points(struct drm_i915_private *i915,
> const struct intel_bw_state *old_bw_state,
> struct intel_bw_state *new_bw_state)
> {
> - unsigned int max_bw_point = 0;
> - unsigned int max_bw = 0;
> unsigned int num_psf_gv_points = i915->display.bw.max[0].num_psf_gv_points;
> unsigned int num_qgv_points = i915->display.bw.max[0].num_qgv_points;
> u16 psf_points = 0;
> @@ -909,18 +965,6 @@ static int icl_find_qgv_points(struct drm_i915_private *i915,
>
> max_data_rate = i915->display.bw.max[idx].deratedbw[i];
>
> - /*
> - * We need to know which qgv point gives us
> - * maximum bandwidth in order to disable SAGV
> - * if we find that we exceed SAGV block time
> - * with watermarks. By that moment we already
> - * have those, as it is calculated earlier in
> - * intel_atomic_check,
> - */
> - if (max_data_rate > max_bw) {
> - max_bw_point = i;
> - max_bw = max_data_rate;
> - }
> if (max_data_rate >= data_rate)
> qgv_points |= BIT(i);
>
> @@ -964,9 +1008,13 @@ static int icl_find_qgv_points(struct drm_i915_private *i915,
> * cause.
> */
> if (!intel_can_enable_sagv(i915, new_bw_state)) {
> - qgv_points = BIT(max_bw_point);
> - drm_dbg_kms(&i915->drm, "No SAGV, using single QGV point %d\n",
> - max_bw_point);
> + unsigned int max_bw_qgv_point = icl_max_bw_qgv_point(i915, num_active_planes);
> + unsigned int max_bw_psf_gv_point = icl_max_bw_psf_gv_point(i915);
> +
> + qgv_points = BIT(max_bw_qgv_point);
> + psf_points = BIT(max_bw_psf_gv_point);
We didn't restrict the PSF here previously.
> + drm_dbg_kms(&i915->drm, "No SAGV, using single QGV point %d PSF GV point %d\n",
> + max_bw_qgv_point, max_bw_psf_gv_point);
> }
>
> /*
> --
> 2.37.3
--
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