On Mon, Mar 25, 2024 at 03:01:56PM +0200, Vinod Govindapillai wrote:
> From: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
>
> There could be multiple qgv and psf gv points with similar values
> In case if we need to set one such QGV or psf gv point where there
> could be duplicate entries, we would have to select all those
> points. Otherwise pcode might reject the GV configuration. We do
> handle this when we set appropriate qgv and psf gv as part of
> intel_bw_atomic_check calls. But during the bw_init force disable
> QGV points phase, we need to select all those points corresponding
> to the maximum bw as well.
>
> v1: - use the same treatment to qgv points as well (Vinod)
>
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> Signed-off-by: Vinod Govindapillai <vinod.govindapillai@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_bw.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
> index 844d2d9efeb4..20c67474154e 100644
> --- a/drivers/gpu/drm/i915/display/intel_bw.c
> +++ b/drivers/gpu/drm/i915/display/intel_bw.c
> @@ -847,6 +847,8 @@ static unsigned int icl_max_bw_qgv_point_mask(struct drm_i915_private *i915,
> if (max_data_rate > max_bw) {
> max_bw_point_mask = BIT(i);
> max_bw = max_data_rate;
> + } else if (max_data_rate == max_bw) {
> + max_bw_point_mask |= BIT(i);
> }
> }
>
> @@ -866,6 +868,8 @@ static unsigned int icl_max_bw_psf_gv_point_mask(struct drm_i915_private *i915)
> if (max_data_rate > max_bw) {
> max_bw_point_mask = BIT(i);
> max_bw = max_data_rate;
> + } else if (max_data_rate == max_bw) {
> + max_bw_point_mask |= BIT(i);
This doesn't seem entirely safe. What happens if we somehow
have two qgv points with the same bandwidth but different
uderlying clock/gear ratio/etc.?
While such behaviour may not seem entirely sensible, given
that we need to do this stuff at all, I don't think we can
assume any kind of sensible behaviour from pcode here.
So I think we will need to check that the qgv points
being used here are in fact 100% identical.
> }
> }
>
> --
> 2.34.1
--
Ville Syrjälä
Intel
