Re: [PATCH v2 13/20] drm/i915: Always reset in intel_crtc_restore_mode

Daniel Vetter
2015-07-07T10:14:59Z

On Tue, Jul 07, 2015 at 09:08:24AM +0200, Maarten Lankhorst wrote:
> And get rid of things that are no longer true. This function is only
> used for forcing a modeset when encoder properties are changed.
>
> All the existing state is fine in this case, only setting mode_changed
> will force a full recalculation here, and take all the state needed.
>
> The previous commit will prevent unneeded modesets anyway.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> ---
> drivers/gpu/drm/i915/intel_display.c | 58 ++++++++++--------------------------
> 1 file changed, 16 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 16373309dcae..f7b1fc28142c 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13260,63 +13260,37 @@ void intel_crtc_restore_mode(struct drm_crtc *crtc)
> {
> struct drm_device *dev = crtc->dev;
> struct drm_atomic_state *state;
> - struct intel_encoder *encoder;
> - struct intel_connector *connector;
> - struct drm_connector_state *connector_state;
> - struct intel_crtc_state *crtc_state;
> + struct drm_crtc_state *crtc_state;
> int ret;
>
> state = drm_atomic_state_alloc(dev);
> if (!state) {
> - DRM_DEBUG_KMS("[CRTC:%d] mode restore failed, out of memory",
> + DRM_DEBUG_KMS("[CRTC:%d] crtc restore failed, out of memory",
> crtc->base.id);
> return;
> }
>
> - state->acquire_ctx = dev->mode_config.acquire_ctx;
> -
> - /* The force restore path in the HW readout code relies on the staged
> - * config still keeping the user requested config while the actual
> - * state has been overwritten by the configuration read from HW. We
> - * need to copy the staged config to the atomic state, otherwise the
> - * mode set will just reapply the state the HW is already in. */
> - for_each_intel_encoder(dev, encoder) {
> - if (encoder->base.crtc != crtc)
> - continue;
> + state->acquire_ctx = drm_modeset_legacy_acquire_ctx(crtc);
>
> - for_each_intel_connector(dev, connector) {
> - if (connector->base.state->best_encoder !=
> - &encoder->base)
> - continue;
> -
> - connector_state = drm_atomic_get_connector_state(state, &connector->base);
> - if (IS_ERR(connector_state)) {
> - DRM_DEBUG_KMS("Failed to add [CONNECTOR:%d:%s] to state: %ld\n",
> - connector->base.base.id,
> - connector->base.name,
> - PTR_ERR(connector_state));
> - continue;
> - }
> +retry:
> + crtc_state = drm_atomic_get_crtc_state(state, crtc);
> + ret = PTR_ERR_OR_ZERO(crtc_state);
> + if (!ret) {
> + if (!crtc_state->active)
> + goto out;
>
> - connector_state->crtc = crtc;
> - }
> + crtc_state->mode_changed = true;
> + ret = intel_set_mode(state);

I think here (instead of the hw state readout/restore code) we must do a
full compute config of the pipe state - most of the connector properties
need that to get reflected. Should be easy to test by changing the panel
upscaling property. Hence I think we should be able to run a full-blown
drm_atomic_commit here.
-Daniel

> }
>
> - crtc_state = intel_atomic_get_crtc_state(state, to_intel_crtc(crtc));
> - if (IS_ERR(crtc_state)) {
> - DRM_DEBUG_KMS("Failed to add [CRTC:%d] to state: %ld\n",
> - crtc->base.id, PTR_ERR(crtc_state));
> - drm_atomic_state_free(state);
> - return;
> + if (ret == -EDEADLK) {
> + drm_atomic_state_clear(state);
> + drm_modeset_backoff(state->acquire_ctx);
> + goto retry;
> }
>
> - drm_mode_copy(&crtc_state->base.mode, &crtc->mode);
> -
> - intel_modeset_setup_plane_state(state, crtc, &crtc->mode,
> - crtc->primary->fb, crtc->x, crtc->y);
> -
> - ret = intel_set_mode(state);
> if (ret)
> +out:
> drm_atomic_state_free(state);
> }
>
> --
> 2.1.0
>
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--
Daniel Vetter
Software Engineer, Intel Corporation