On Thu, Sep 03, 2020 at 09:38:31PM +0300, Ville Syrjälä wrote: > On Wed, Jul 15, 2020 at 03:42:16PM -0700, Manasi Navare wrote: > > From: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > > > > When the clock is higher than the dotclock, try with 2 pipes enabled. > > If we can enable 2, then we will go into big joiner mode, and steal > > the adjacent crtc. > > > > This only links the crtc's in software, no hardware or plane > > programming is done yet. Blobs are also copied from the master's > > crtc_state, so it doesn't depend at commit time on the other > > crtc_state. > > > > v3: > > * Manual Rebase (Manasi) > > Changes since v1: > > - Rename pipe timings to transcoder timings, as they are now different. > > Changes since v2: > > - Rework bigjoiner checks; always disable slave when recalculating > > master. No need to have a separate bigjoiner pass any more. > > - Use pipe_mode instead of transcoder_mode, to clean up the code. > > > > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > > Signed-off-by: Manasi Navare <manasi.d.navare@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/display/intel_atomic.c | 9 +- > > drivers/gpu/drm/i915/display/intel_atomic.h | 3 +- > > drivers/gpu/drm/i915/display/intel_display.c | 201 ++++++++++++++++-- > > .../drm/i915/display/intel_display_types.h | 9 + > > drivers/gpu/drm/i915/display/intel_dp.c | 22 +- > > 5 files changed, 211 insertions(+), 33 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c > > index 630f49b7aa01..b9dcdc74a10d 100644 > > --- a/drivers/gpu/drm/i915/display/intel_atomic.c > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c > > @@ -270,14 +270,15 @@ void intel_crtc_free_hw_state(struct intel_crtc_state *crtc_state) > > intel_crtc_put_color_blobs(crtc_state); > > } > > > > -void intel_crtc_copy_color_blobs(struct intel_crtc_state *crtc_state) > > +void intel_crtc_copy_color_blobs(struct intel_crtc_state *crtc_state, > > + const struct intel_crtc_state *from_crtc_state) > > { > > drm_property_replace_blob(&crtc_state->hw.degamma_lut, > > - crtc_state->uapi.degamma_lut); > > + from_crtc_state->uapi.degamma_lut); > > drm_property_replace_blob(&crtc_state->hw.gamma_lut, > > - crtc_state->uapi.gamma_lut); > > + from_crtc_state->uapi.gamma_lut); > > drm_property_replace_blob(&crtc_state->hw.ctm, > > - crtc_state->uapi.ctm); > > + from_crtc_state->uapi.ctm); > > } > > > > /** > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h b/drivers/gpu/drm/i915/display/intel_atomic.h > > index 11146292b06f..fc556c032c8f 100644 > > --- a/drivers/gpu/drm/i915/display/intel_atomic.h > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.h > > @@ -43,7 +43,8 @@ struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc *crtc); > > void intel_crtc_destroy_state(struct drm_crtc *crtc, > > struct drm_crtc_state *state); > > void intel_crtc_free_hw_state(struct intel_crtc_state *crtc_state); > > -void intel_crtc_copy_color_blobs(struct intel_crtc_state *crtc_state); > > +void intel_crtc_copy_color_blobs(struct intel_crtc_state *crtc_state, > > + const struct intel_crtc_state *from_crtc_state); > > struct drm_atomic_state *intel_atomic_state_alloc(struct drm_device *dev); > > void intel_atomic_state_free(struct drm_atomic_state *state); > > void intel_atomic_state_clear(struct drm_atomic_state *state); > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > > index 3ecb642805a6..955e19abb563 100644 > > --- a/drivers/gpu/drm/i915/display/intel_display.c > > +++ b/drivers/gpu/drm/i915/display/intel_display.c > > @@ -8016,9 +8016,24 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc, > > struct intel_crtc_state *pipe_config) > > { > > struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); > > - const struct drm_display_mode *pipe_mode = &pipe_config->hw.pipe_mode; > > + struct drm_display_mode *pipe_mode = &pipe_config->hw.pipe_mode; > > int clock_limit = dev_priv->max_dotclk_freq; > > > > + *pipe_mode = pipe_config->hw.adjusted_mode; > > + > > + /* Adjust pipe_mode for bigjoiner, with half the horizontal mode */ > > + if (pipe_config->bigjoiner) { > > + pipe_mode->crtc_clock /= 2; > > + pipe_mode->crtc_hdisplay /= 2; > > + pipe_mode->crtc_hblank_start /= 2; > > + pipe_mode->crtc_hblank_end /= 2; > > + pipe_mode->crtc_hsync_start /= 2; > > + pipe_mode->crtc_hsync_end /= 2; > > + pipe_mode->crtc_htotal /= 2; > > + pipe_mode->crtc_hskew /= 2; > > + pipe_config->pipe_src_w /= 2; > > + } > > + > > if (INTEL_GEN(dev_priv) < 4) { > > clock_limit = dev_priv->max_cdclk_freq * 9 / 10; > > > > @@ -8079,7 +8094,7 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc, > > * WaPruneModeWithIncorrectHsyncOffset:ctg,elk,ilk,snb,ivb,vlv,hsw. > > */ > > if ((INTEL_GEN(dev_priv) > 4 || IS_G4X(dev_priv)) && > > - pipe_mode->crtc_hsync_start == pipe_mode->crtc_hdisplay) > > + pipe_config->hw.adjusted_mode.crtc_hsync_start == pipe_mode->crtc_hdisplay) > > What's the deal here? I think I asked this same question ages ago > already... Yea I have no idea why we compare pipe_config->hw.adjusted_mode.crtc_hsync_start with pipe_mode->crtc_hdisplay? It should just be a check of pipe_mode->crtc_hsync_start == pipe_mode->crtc_hdisplay so no change needed Ville, do you agree? > > > return -EINVAL; > > > > intel_crtc_compute_pixel_rate(pipe_config); > > @@ -12433,7 +12448,7 @@ static bool encoders_cloneable(const struct intel_encoder *a, > > b->cloneable & (1 << a->type)); > > } > > > > -static bool check_single_encoder_cloning(struct drm_atomic_state *state, > > +static bool check_single_encoder_cloning(struct intel_atomic_state *state, > > struct intel_crtc *crtc, > > struct intel_encoder *encoder) > > { > > @@ -12442,7 +12457,7 @@ static bool check_single_encoder_cloning(struct drm_atomic_state *state, > > struct drm_connector_state *connector_state; > > int i; > > > > - for_each_new_connector_in_state(state, connector, connector_state, i) { > > + for_each_new_connector_in_state(&state->base, connector, connector_state, i) { > > if (connector_state->crtc != &crtc->base) > > continue; > > > > @@ -12682,6 +12697,7 @@ static int intel_crtc_atomic_check(struct intel_atomic_state *state, > > > > if (mode_changed && crtc_state->hw.enable && > > dev_priv->display.crtc_compute_clock && > > + !crtc_state->bigjoiner_slave && > > !drm_WARN_ON(&dev_priv->drm, crtc_state->shared_dpll)) { > > ret = dev_priv->display.crtc_compute_clock(crtc, crtc_state); > > if (ret) > > @@ -13206,18 +13222,31 @@ static bool check_digital_port_conflicts(struct intel_atomic_state *state) > > } > > > > static void > > -intel_crtc_copy_uapi_to_hw_state_nomodeset(struct intel_crtc_state *crtc_state) > > +intel_crtc_copy_uapi_to_hw_state_nomodeset(struct intel_atomic_state *state, > > + struct intel_crtc_state *crtc_state) > > { > > - intel_crtc_copy_color_blobs(crtc_state); > > + const struct intel_crtc_state *from_crtc_state = crtc_state; > > + > > + if (crtc_state->bigjoiner_slave) { > > + from_crtc_state = intel_atomic_get_new_crtc_state(state, > > + crtc_state->bigjoiner_linked_crtc); > > + > > + /* No need to copy state if the master state is unchanged */ > > + if (!from_crtc_state) > > + return; > > + } > > + > > + intel_crtc_copy_color_blobs(crtc_state, from_crtc_state); > > } > > > > static void > > -intel_crtc_copy_uapi_to_hw_state(struct intel_crtc_state *crtc_state) > > +intel_crtc_copy_uapi_to_hw_state(struct intel_atomic_state *state, > > + struct intel_crtc_state *crtc_state) > > { > > crtc_state->hw.enable = crtc_state->uapi.enable; > > crtc_state->hw.active = crtc_state->uapi.active; > > crtc_state->hw.pipe_mode = crtc_state->hw.adjusted_mode = crtc_state->uapi.adjusted_mode; > > - intel_crtc_copy_uapi_to_hw_state_nomodeset(crtc_state); > > + intel_crtc_copy_uapi_to_hw_state_nomodeset(state, crtc_state); > > } > > > > static void intel_crtc_copy_hw_to_uapi_state(struct intel_crtc_state *crtc_state, > > @@ -13240,7 +13269,49 @@ static void intel_crtc_copy_hw_to_uapi_state(struct intel_crtc_state *crtc_state > > } > > > > static int > > -intel_crtc_prepare_cleared_state(struct intel_crtc_state *crtc_state) > > +copy_bigjoiner_crtc_state(struct intel_crtc_state *crtc_state, > > + const struct intel_crtc_state *from_crtc_state) > > +{ > > + struct intel_crtc_state *saved_state; > > + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); > > + > > + saved_state = kmemdup(from_crtc_state, sizeof(*saved_state), GFP_KERNEL); > > + if (!saved_state) > > + return -ENOMEM; > > + > > + saved_state->uapi = crtc_state->uapi; > > + saved_state->scaler_state = crtc_state->scaler_state; > > + saved_state->shared_dpll = crtc_state->shared_dpll; > > + saved_state->dpll_hw_state = crtc_state->dpll_hw_state; > > + saved_state->crc_enabled = crtc_state->crc_enabled; > > + > > + intel_crtc_free_hw_state(crtc_state); > > + memcpy(crtc_state, saved_state, sizeof(*crtc_state)); > > + kfree(saved_state); > > + > > + /* Re-init hw state */ > > + memset(&crtc_state->hw, 0, sizeof(saved_state->hw)); > > + crtc_state->hw.enable = from_crtc_state->hw.enable; > > + crtc_state->hw.active = from_crtc_state->hw.active; > > + crtc_state->hw.pipe_mode = from_crtc_state->hw.pipe_mode; > > + crtc_state->hw.adjusted_mode = from_crtc_state->hw.adjusted_mode; > > + > > + /* Some fixups */ > > + crtc_state->uapi.mode_changed = from_crtc_state->uapi.mode_changed; > > + crtc_state->uapi.connectors_changed = from_crtc_state->uapi.connectors_changed; > > + crtc_state->uapi.active_changed = from_crtc_state->uapi.active_changed; > > + crtc_state->nv12_planes = crtc_state->c8_planes = crtc_state->update_planes = 0; > > + crtc_state->bigjoiner_linked_crtc = to_intel_crtc(from_crtc_state->uapi.crtc); > > + crtc_state->bigjoiner_slave = true; > > + crtc_state->cpu_transcoder = (enum transcoder)crtc->pipe; > > + crtc_state->has_audio = false; > > + > > + return 0; > > +} > > + > > +static int > > +intel_crtc_prepare_cleared_state(struct intel_atomic_state *state, > > + struct intel_crtc_state *crtc_state) > > { > > struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); > > struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); > > @@ -13276,16 +13347,16 @@ intel_crtc_prepare_cleared_state(struct intel_crtc_state *crtc_state) > > crtc_state->uapi.mode.private_flags = 0; > > crtc_state->uapi.adjusted_mode.private_flags = 0; > > > > - intel_crtc_copy_uapi_to_hw_state(crtc_state); > > + intel_crtc_copy_uapi_to_hw_state(state, crtc_state); > > > > return 0; > > } > > > > static int > > -intel_modeset_pipe_config(struct intel_crtc_state *pipe_config) > > +intel_modeset_pipe_config(struct intel_atomic_state *state, > > + struct intel_crtc_state *pipe_config) > > { > > struct drm_crtc *crtc = pipe_config->uapi.crtc; > > - struct drm_atomic_state *state = pipe_config->uapi.state; > > struct drm_i915_private *i915 = to_i915(pipe_config->uapi.crtc->dev); > > struct drm_connector *connector; > > struct drm_connector_state *connector_state; > > @@ -13327,7 +13398,7 @@ intel_modeset_pipe_config(struct intel_crtc_state *pipe_config) > > &pipe_config->pipe_src_w, > > &pipe_config->pipe_src_h); > > > > - for_each_new_connector_in_state(state, connector, connector_state, i) { > > + for_each_new_connector_in_state(&state->base, connector, connector_state, i) { > > struct intel_encoder *encoder = > > to_intel_encoder(connector_state->best_encoder); > > > > @@ -13365,7 +13436,7 @@ intel_modeset_pipe_config(struct intel_crtc_state *pipe_config) > > * adjust it according to limitations or connector properties, and also > > * a chance to reject the mode entirely. > > */ > > - for_each_new_connector_in_state(state, connector, connector_state, i) { > > + for_each_new_connector_in_state(&state->base, connector, connector_state, i) { > > struct intel_encoder *encoder = > > to_intel_encoder(connector_state->best_encoder); > > > > @@ -13422,8 +13493,6 @@ intel_modeset_pipe_config(struct intel_crtc_state *pipe_config) > > * drm_atomic_helper_update_legacy_modeset_state() happy > > */ > > pipe_config->uapi.adjusted_mode = pipe_config->hw.adjusted_mode; > > - /* without bigjoiner, pipe_mode == adjusted_mode */ > > - pipe_config->hw.pipe_mode = pipe_config->hw.adjusted_mode; > > > > return 0; > > } > > @@ -14820,6 +14889,75 @@ static bool intel_cpu_transcoders_need_modeset(struct intel_atomic_state *state, > > return false; > > } > > > > +static int intel_atomic_check_bigjoiner(struct intel_atomic_state *state, > > + struct intel_crtc *crtc, > > + struct intel_crtc_state *old_crtc_state, > > + struct intel_crtc_state *new_crtc_state) > > +{ > > + struct drm_i915_private *dev_priv = to_i915(state->base.dev); > > + struct intel_crtc_state *slave_crtc_state, *master_crtc_state; > > + struct intel_crtc *slave, *master; > > + > > + /* slave being enabled, is master is still claiming this crtc? */ > > + if (old_crtc_state->bigjoiner_slave) { > > + slave = crtc; > > + master = old_crtc_state->bigjoiner_linked_crtc; > > + master_crtc_state = intel_atomic_get_new_crtc_state(state, master); > > + if (!master_crtc_state || !needs_modeset(master_crtc_state)) > > + goto claimed; > > + } > > + > > + if (!new_crtc_state->bigjoiner) > > + return 0; > > + > > + if (1 + crtc->pipe >= INTEL_NUM_PIPES(dev_priv)) { > > + DRM_DEBUG_KMS("[CRTC:%d:%s] Big joiner configuration requires " > > + "CRTC + 1 to be used, doesn't exist\n", > > + crtc->base.base.id, crtc->base.name); > > + return -EINVAL; > > + } > > + > > + slave = new_crtc_state->bigjoiner_linked_crtc = > > + intel_get_crtc_for_pipe(dev_priv, crtc->pipe + 1); > > + slave_crtc_state = intel_atomic_get_crtc_state(&state->base, slave); > > + master = crtc; > > + if (IS_ERR(slave_crtc_state)) > > + return PTR_ERR(slave_crtc_state); > > + > > + /* master being enabled, slave was already configured? */ > > + if (slave_crtc_state->uapi.enable) > > + goto claimed; > > + > > + DRM_DEBUG_KMS("[CRTC:%d:%s] Used as slave for big joiner\n", > > + slave->base.base.id, slave->base.name); > > + > > + return copy_bigjoiner_crtc_state(slave_crtc_state, new_crtc_state); > > + > > +claimed: > > + DRM_DEBUG_KMS("[CRTC:%d:%s] Slave is enabled as normal CRTC, but " > > + "[CRTC:%d:%s] claiming this CRTC for bigjoiner.\n", > > + slave->base.base.id, slave->base.name, > > + master->base.base.id, master->base.name); > > + return -EINVAL; > > +} > > + > > +static int kill_bigjoiner_slave(struct intel_atomic_state *state, > > + struct intel_crtc_state *master_crtc_state) > > +{ > > + struct intel_crtc_state *slave_crtc_state = > > + intel_atomic_get_crtc_state(&state->base, > > + master_crtc_state->bigjoiner_linked_crtc); > > + > > + if (IS_ERR(slave_crtc_state)) > > + return PTR_ERR(slave_crtc_state); > > + > > + slave_crtc_state->bigjoiner = master_crtc_state->bigjoiner = false; > > + slave_crtc_state->bigjoiner_slave = master_crtc_state->bigjoiner_slave = false; > > + slave_crtc_state->bigjoiner_linked_crtc = master_crtc_state->bigjoiner_linked_crtc = NULL; > > + intel_crtc_copy_uapi_to_hw_state(state, slave_crtc_state); > > + return 0; > > +} > > + > > /** > > * intel_atomic_check - validate state object > > * @dev: drm device > > @@ -14849,19 +14987,36 @@ static int intel_atomic_check(struct drm_device *dev, > > new_crtc_state, i) { > > if (!needs_modeset(new_crtc_state)) { > > /* Light copy */ > > - intel_crtc_copy_uapi_to_hw_state_nomodeset(new_crtc_state); > > + intel_crtc_copy_uapi_to_hw_state_nomodeset(state, new_crtc_state); > > > > continue; > > } > > > > - ret = intel_crtc_prepare_cleared_state(new_crtc_state); > > + /* Kill old bigjoiner link, we may re-establish afterwards */ > > + if (old_crtc_state->bigjoiner && !old_crtc_state->bigjoiner_slave) { > > + ret = kill_bigjoiner_slave(state, new_crtc_state); > > + if (ret) > > + goto fail; > > + } > > + > > + if (!new_crtc_state->uapi.enable) { > > + if (!new_crtc_state->bigjoiner_slave) { > > + intel_crtc_copy_uapi_to_hw_state(state, new_crtc_state); > > + any_ms = true; > > + } > > I'm confused. Where do we add the other pipe to the state if there are no > modesets involved? > We get crtc state for pipe + 1 (stolen pipe) in intel_atomic_check_bigjoiner In the testing now I see that we correctly steal the pipe and do modeset on that Whats your concern here, could ypu elaborate? Manasi > > + continue; > > + } > > + > > + ret = intel_crtc_prepare_cleared_state(state, new_crtc_state); > > if (ret) > > goto fail; > > > > - if (!new_crtc_state->hw.enable) > > - continue; > > + ret = intel_modeset_pipe_config(state, new_crtc_state); > > + if (ret) > > + goto fail; > > > > - ret = intel_modeset_pipe_config(new_crtc_state); > > + ret = intel_atomic_check_bigjoiner(state, crtc, old_crtc_state, > > + new_crtc_state); > > if (ret) > > goto fail; > > } > > @@ -15193,7 +15348,9 @@ static void intel_update_crtc(struct intel_atomic_state *state, > > > > commit_pipe_config(state, crtc); > > > > - if (INTEL_GEN(dev_priv) >= 9) > > + if (new_crtc_state->bigjoiner) { > > + /* Not supported yet */ > > + } else if (INTEL_GEN(dev_priv) >= 9) > > skl_update_planes_on_crtc(state, crtc); > > else > > i9xx_update_planes_on_crtc(state, crtc); > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h > > index c52c8f42df68..4694cfd90a0a 100644 > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h > > @@ -1053,6 +1053,15 @@ struct intel_crtc_state { > > /* enable pipe csc? */ > > bool csc_enable; > > > > + /* enable pipe big joiner? */ > > + bool bigjoiner; > > + > > + /* big joiner slave crtc? */ > > + bool bigjoiner_slave; > > + > > + /* linked crtc for bigjoiner, either slave or master */ > > + struct intel_crtc *bigjoiner_linked_crtc; > > + > > /* Display Stream compression state */ > > struct { > > bool compression_enable; > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > > index fbfea99fd804..29f45d2206af 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > @@ -2247,6 +2247,15 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp, > > pipe_config->port_clock = intel_dp->common_rates[limits->max_clock]; > > pipe_config->lane_count = limits->max_lane_count; > > > > + if (adjusted_mode->crtc_clock > intel_dp_max_dotclock(intel_dp, false)) { > > + if (adjusted_mode->crtc_clock > intel_dp_max_dotclock(intel_dp, true)) { > > + DRM_DEBUG_KMS("Clock rate too high for big joiner\n"); > > + return -EINVAL; > > + } > > + pipe_config->bigjoiner = true; > > + DRM_DEBUG_KMS("Using bigjoiner configuration\n"); > > + } > > + > > if (intel_dp_is_edp(intel_dp)) { > > pipe_config->dsc.compressed_bpp = > > min_t(u16, drm_edp_dsc_sink_output_bpp(intel_dp->dsc_dpcd) >> 4, > > @@ -2264,12 +2273,12 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp, > > pipe_config->lane_count, > > adjusted_mode->crtc_clock, > > adjusted_mode->crtc_hdisplay, > > - false); > > + pipe_config->bigjoiner); > > dsc_dp_slice_count = > > intel_dp_dsc_get_slice_count(intel_dp, > > adjusted_mode->crtc_clock, > > adjusted_mode->crtc_hdisplay, > > - false); > > + pipe_config->bigjoiner); > > if (!dsc_max_output_bpp || !dsc_dp_slice_count) { > > drm_dbg_kms(&dev_priv->drm, > > "Compressed BPP/Slice Count not supported\n"); > > @@ -2285,14 +2294,15 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp, > > * is greater than the maximum Cdclock and if slice count is even > > * then we need to use 2 VDSC instances. > > */ > > - if (adjusted_mode->crtc_clock > dev_priv->max_cdclk_freq) { > > - if (pipe_config->dsc.slice_count > 1) { > > - pipe_config->dsc.dsc_split = true; > > - } else { > > + if (adjusted_mode->crtc_clock > dev_priv->max_cdclk_freq || > > + pipe_config->bigjoiner) { > > + if (pipe_config->dsc.slice_count < 2) { > > drm_dbg_kms(&dev_priv->drm, > > "Cannot split stream to use 2 VDSC instances\n"); > > return -EINVAL; > > } > > + > > + pipe_config->dsc.dsc_split = true; > > } > > > > ret = intel_dp_dsc_compute_params(&dig_port->base, pipe_config); > > -- > > 2.19.1 > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx > > -- > Ville Syrjälä > Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx