On Thu, Mar 26, 2020 at 08:10:00PM +0200, Stanislav Lisovskiy wrote:
> Addressing one of the comments, recommending to extract platform
> specific code from intel_can_enable_sagv as a preparation, before
> we are going to add support for tgl+.
>
> Current code in intel_can_enable_sagv is valid only for skl,
> so this patch adds also proper support for icl, subsequent
> patches will add support for tgl+, combined with other required
> changes.
>
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/intel_pm.c | 89 ++++++++++++++++++++++-----------
> 1 file changed, 61 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index f8d62d1977ac..64193b098175 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3757,41 +3757,24 @@ intel_disable_sagv(struct drm_i915_private *dev_priv)
> return 0;
> }
>
> -bool intel_can_enable_sagv(struct intel_atomic_state *state)
> +static bool icl_can_enable_sagv_on_pipe(struct intel_crtc_state *crtc_state)
icl_crtc_can_enable_sagv()/etc. would be more consistent with existing
practices. crtc_state can be const.
> {
> - struct drm_device *dev = state->base.dev;
> + struct drm_device *dev = crtc_state->uapi.crtc->dev;
IMO just remove this 'dev' variable.
> struct drm_i915_private *dev_priv = to_i915(dev);
> struct intel_crtc *crtc;
> struct intel_plane *plane;
> - struct intel_crtc_state *crtc_state;
> - enum pipe pipe;
> + struct intel_plane_state *plane_state;
const
> int level, latency;
>
> - if (!intel_has_sagv(dev_priv))
> - return false;
> + crtc = to_intel_crtc(crtc_state->uapi.crtc);
Initialize when declaring.
>
> - /*
> - * If there are no active CRTCs, no additional checks need be performed
> - */
> - if (hweight8(state->active_pipes) == 0)
> - return true;
> -
> - /*
> - * SKL+ workaround: bspec recommends we disable SAGV when we have
> - * more then one pipe enabled
> - */
> - if (hweight8(state->active_pipes) > 1)
> - return false;
> -
> - /* Since we're now guaranteed to only have one active CRTC... */
> - pipe = ffs(state->active_pipes) - 1;
> - crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
> - crtc_state = to_intel_crtc_state(crtc->base.state);
We seem to be missing a hw.active check.
> -
> - if (crtc_state->hw.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE)
> + if (crtc_state->hw.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE) {
> + DRM_DEBUG_KMS("No SAGV for interlaced mode on pipe %c\n",
> + pipe_name(crtc->pipe));
> return false;
> + }
>
> - for_each_intel_plane_on_crtc(dev, crtc, plane) {
> + intel_atomic_crtc_state_for_each_plane_state(plane, plane_state, crtc_state) {
> struct skl_plane_wm *wm =
> &crtc_state->wm.skl.optimal.planes[plane->id];
>
> @@ -3807,7 +3790,7 @@ bool intel_can_enable_sagv(struct intel_atomic_state *state)
> latency = dev_priv->wm.skl_latency[level];
>
> if (skl_needs_memory_bw_wa(dev_priv) &&
> - plane->base.state->fb->modifier ==
> + plane_state->uapi.fb->modifier ==
> I915_FORMAT_MOD_X_TILED)
> latency += 15;
>
> @@ -3816,8 +3799,58 @@ bool intel_can_enable_sagv(struct intel_atomic_state *state)
> * incur memory latencies higher than sagv_block_time_us we
> * can't enable SAGV.
> */
> - if (latency < dev_priv->sagv_block_time_us)
> + if (latency < dev_priv->sagv_block_time_us) {
> + DRM_DEBUG_KMS("Latency %d < sagv block time %d, no SAGV for pipe %c\n",
> + latency, dev_priv->sagv_block_time_us, pipe_name(crtc->pipe));
> return false;
How much noise will these debugs generate?
> + }
> + }
> +
> + return true;
> +}
> +
> +static bool skl_can_enable_sagv_on_pipe(struct intel_crtc_state *crtc_state)
> +{
> + struct intel_atomic_state *state = to_intel_atomic_state(crtc_state->uapi.state);
> +
> + /*
> + * It has been recommended that for Gen 9 we switch SAGV off when
> + * multiple pipes are used.
> + */
> + if (hweight8(state->active_pipes) > 1)
> + return false;
> +
> + /*
> + * Besides active pipe limitation, rest of checks pretty much match ICL
> + * so no need to duplicate code
> + */
> + return icl_can_enable_sagv_on_pipe(crtc_state);
> +}
> +
> +bool intel_can_enable_sagv(struct intel_atomic_state *state)
> +{
> + struct drm_device *dev = state->base.dev;
Pls don't add needless 'dev' variables.
> + struct drm_i915_private *dev_priv = to_i915(dev);
> + struct intel_crtc *crtc;
> + struct intel_crtc_state *crtc_state;
const
> + int i;
> +
> + if (!intel_has_sagv(dev_priv))
> + return false;
> +
> + /*
> + * If there are no active CRTCs, no additional checks need be performed
> + */
> + if (hweight8(state->active_pipes) == 0)
> + return true;
Seems pointless.
> +
> + for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
Hmm. I think this is now temporarily busted since we only consider
the crtcs in the state. Would seem like we need to introduce the
sagv bitmaks first/at the same time as we do this.
> + if (INTEL_GEN(dev_priv) <= 9) {
> + if (!skl_can_enable_sagv_on_pipe(crtc_state))
> + return false;
> + } else if (!icl_can_enable_sagv_on_pipe(crtc_state)) {
> + return false;
> + }
Very hard to read if-else construct. Plase make it consistent for both
branches, and put the icl+ case first.
> }
>
> return true;
> --
> 2.24.1.485.gad05a3d8e5
--
Ville Syrjälä
Intel
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