On Mon, 2016-05-09 at 10:43 +0000, R, Durgadoss wrote: > Hi Ander, > > Thanks for looking at it. > Few queries below.. > > > > > -----Original Message----- > > From: Ander Conselvan De Oliveira [mailto:conselvan2@xxxxxxxxx] > > Sent: Friday, May 6, 2016 6:39 PM > > To: R, Durgadoss <durgadoss.r@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > Subject: Re: [PATCHv4 3/3] drm/i915/dp: Enable Upfront link > > training for typeC DP support on BXT > > > > On Mon, 2016-04-18 at 19:01 +0530, Durgadoss R wrote: > > > > > > To support USB type C alternate DP mode, the display driver needs to > > > know the number of lanes required by the DP panel as well as number > > > of lanes that can be supported by the type-C cable. Sometimes, the > > > type-C cable may limit the bandwidth even if Panel can support > > > more lanes. To address these scenarios, the display driver will > > > start link training with max lanes, and if that fails, the driver > > > falls back to x2 lanes; and repeats this procedure for all > > > bandwidth/lane configurations. > > > > > > * Since link training is done before modeset only the port > > > (and not pipe/planes) and its associated PLLs are enabled. > > > * On DP hotplug: Directly start link training on the crtc > > > associated with the DP encoder. > > > * On Connected boot scenarios: When booted with an LFP and a DP, > > > typically, BIOS brings up DP. In these cases, we disable the > > > crtc and then do upfront link training; and let the subsequent > > > modeset re-enable the crtc. > > > * All local changes made for upfront link training are reset > > > to their previous values once it is done; so that the > > > subsequent modeset is not aware of these changes. > > > > > > Changes since v3: > > > * Fixed a return value on BXT check > > > * Reworked on top of bxt_ddi_pll_select split from Ander > > > * Renamed from ddi_upfront to bxt_upfront since the > > > upfront logic includes BXT specific functions for now. > > > Changes since v2: > > > * Rebased on top of latest dpll_mgr.c code and > > > latest HPD related clean ups. > > > * Corrected return values from upfront (Ander) > > > * Corrected atomic locking for upfront in intel_dp.c (Ville) > > > Changes since v1: > > > * all pll related functions inside ddi.c > > > > > > Signed-off-by: Durgadoss R <durgadoss.r@xxxxxxxxx> > > > --- > > > drivers/gpu/drm/i915/intel_ddi.c | 73 ++++++++++++++++ > > > drivers/gpu/drm/i915/intel_dp.c | 180 > > > ++++++++++++++++++++++++++++++++++++++- > > > drivers/gpu/drm/i915/intel_drv.h | 5 ++ > > > 3 files changed, 256 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_ddi.c > > > b/drivers/gpu/drm/i915/intel_ddi.c > > > index 96234c5..f7fa3db 100644 > > > --- a/drivers/gpu/drm/i915/intel_ddi.c > > > +++ b/drivers/gpu/drm/i915/intel_ddi.c > > > @@ -2268,6 +2268,79 @@ intel_ddi_init_hdmi_connector(struct > > intel_digital_port > > > > > > *intel_dig_port) > > > return connector; > > > } > > > > > > +int intel_bxt_upfront_link_train(struct intel_dp *intel_dp, > > > + struct intel_crtc *crtc) > > > +{ > > > + struct intel_connector *connector = intel_dp->attached_connector; > > > + struct intel_encoder *encoder = connector->encoder; > > > + struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > > > + struct intel_shared_dpll *pll; > > > + struct intel_shared_dpll_config tmp_pll_config; > > > + struct bxt_clk_div clk_div = {0}; > > > + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); > > > + enum intel_dpll_id dpll_id = (enum intel_dpll_id)dig_port->port; > > > + uint8_t link_bw, lane_count; > > > + > > > + if (WARN_ON(!crtc)) > > > + return -EINVAL; > > > + > > > + /* Initialize with Max Link rate & lane count supported by panel > > > */ > > > + link_bw = intel_dp->dpcd[DP_MAX_LINK_RATE]; > > > + lane_count = drm_dp_max_lane_count(intel_dp->dpcd); > > What if the panel supports HBR3? We should use the maximum common rate > Ok, today that will add one more iteration of Link training before going > down to a supported rate. > > > > > between source and sink. And it would be nice if those details where in > > intel_dp.c. > > Ideally, the platform specific part would take link rate and lane count as > > arguments and just do the pll/encoder enabling/disabling. > May be with the new {link_bw/lane_count}_upfront variables in intel_dp > structure, > we could do this easily. Will try this implementation and see how it comes up. > > > > > > > > > > > + > > > + mutex_lock(&dev_priv->dpll_lock); > > > + /* > > > + * FIXME: Works only for BXT. > > > + * Select the required PLL. This works for platforms where > > > + * there is no shared DPLL. > > > + */ > > > + pll = &dev_priv->shared_dplls[dpll_id]; > > > + if (WARN_ON(pll->active_mask)) { > > > + DRM_ERROR("Shared DPLL already in use. > > active_mask:%x\n", > > > > > > pll->active_mask); > > > + mutex_unlock(&dev_priv->dpll_lock); > > > + return -EINVAL; > > > + } > > > + > > > + tmp_pll_config = pll->config; > > > + > > > + DRM_DEBUG_KMS("Using pipe %c with pll %s\n", > > > + pipe_name(crtc->pipe), pll->name); > > > + do { > > > + crtc->config->port_clock = > > > drm_dp_bw_code_to_link_rate(link_bw); > > > + crtc->config->lane_count = lane_count; > > > + > > > + bxt_ddi_dp_pll_dividers(crtc->config->port_clock, > > > &clk_div); > > > + if (!bxt_ddi_set_dpll_hw_state(crtc->config->port_clock, > > > + &clk_div, &pll->config.hw_state)) > > > { > > > + DRM_ERROR("Could not setup DPLL\n"); > > > + goto exit_pll; > > > + } > > > + > > > + /* Enable PLL followed by port */ > > > + pll->funcs.enable(dev_priv, pll); > > > + encoder->pre_enable(encoder); > > > + > > > + /* Check if link training passed; if so update DPCD */ > > > + if (intel_dp->train_set_valid) > > > + intel_dp_update_dpcd_params(intel_dp); > > > + > > > + /* Disable port followed by PLL for next retry/clean up > > > */ > > > + encoder->post_disable(encoder); > > > + pll->funcs.disable(dev_priv, pll); > > > + > > > + } while (!intel_dp->train_set_valid && > > > + intel_dp_get_link_retry_params(intel_dp, &lane_count, > > > &link_bw)); > > > + > > > + DRM_DEBUG_KMS("Upfront link train %s: lanes:%d bw:%d\n", > > > + intel_dp->train_set_valid ? "Passed" : "Failed", lane_count, > > > link_bw); > > > + > > > +exit_pll: > > > + pll->config = tmp_pll_config; > > > + mutex_unlock(&dev_priv->dpll_lock); > > > + > > > + return intel_dp->train_set_valid ? 0 : -1; > > > +} > > > + > > > void intel_ddi_init(struct drm_device *dev, enum port port) > > > { > > > struct drm_i915_private *dev_priv = dev->dev_private; > > > diff --git a/drivers/gpu/drm/i915/intel_dp.c > > b/drivers/gpu/drm/i915/intel_dp.c > > > > > > index 61ee226..57d7159 100644 > > > --- a/drivers/gpu/drm/i915/intel_dp.c > > > +++ b/drivers/gpu/drm/i915/intel_dp.c > > > @@ -1595,6 +1595,41 @@ void intel_dp_set_link_params(struct intel_dp > > > *intel_dp, > > > intel_dp->lane_count = pipe_config->lane_count; > > > } > > > > > > +void intel_dp_update_dpcd_params(struct intel_dp *intel_dp) > > > +{ > > > + intel_dp->dpcd[DP_MAX_LANE_COUNT] &= > > ~DP_MAX_LANE_COUNT_MASK; > > > > > > + intel_dp->dpcd[DP_MAX_LANE_COUNT] |= > > > + intel_dp->lane_count & > > DP_MAX_LANE_COUNT_MASK; > > > > > > + > > > + intel_dp->dpcd[DP_MAX_LINK_RATE] = > > > + drm_dp_link_rate_to_bw_code(intel_dp- > > > link_rate); > > I think I mentioned this before. I don't think we should update the dpcd > > fields > > directly. Instead, there should be a field for the max rate and lane count > > achieved through upfront link training in struct intel_dp and > > intel_dp_max_link_bw() and intel_dp_max_lane_count() should take that > > into > > account. > I thought we agreed for having that change as a later implementation. > Anyway, it's not a big change; So I will do as part of next revision, > probably as a separate patch. > > > > > > > > > > > +} > > > + > > > +bool intel_dp_get_link_retry_params(struct intel_dp *intel_dp, > > > + uint8_t *lane_count, uint8_t *link_bw) > > > +{ > > > + /* > > > + * As per DP1.3 Spec, retry all link rates for a particular > > > + * lane count value, before reducing number of lanes. > > > + */ > > > + if (*link_bw == DP_LINK_BW_5_4) { > > > + *link_bw = DP_LINK_BW_2_7; > > > + } else if (*link_bw == DP_LINK_BW_2_7) { > > > + *link_bw = DP_LINK_BW_1_62; > > > + } else if (*lane_count == 4) { > > > + *lane_count = 2; > > > + *link_bw = intel_dp_max_link_bw(intel_dp); > > > + } else if (*lane_count == 2) { > > > + *lane_count = 1; > > > + *link_bw = intel_dp_max_link_bw(intel_dp); > > > + } else { > > > + /* Tried all combinations, so exit */ > > > + return false; > > > + } > > > + > > > + return true; > > > +} > > > + > > > static void intel_dp_prepare(struct intel_encoder *encoder) > > > { > > > struct drm_device *dev = encoder->base.dev; > > > @@ -4548,6 +4583,135 @@ intel_dp_unset_edid(struct intel_dp *intel_dp) > > > intel_dp->has_audio = false; > > > } > > > > > > +static struct intel_crtc_state *intel_dp_upfront_get_crtc_state( > > > + struct intel_crtc *crtc, > > > + struct drm_modeset_acquire_ctx *ctx) > > > +{ > > > + struct drm_device *dev = crtc->base.dev; > > > + struct drm_atomic_state *state; > > > + struct intel_crtc_state *crtc_state; > > > + > > > + state = drm_atomic_state_alloc(dev); > > > + if (!state) > > > + return ERR_PTR(-ENOMEM); > > > + > > > + state->acquire_ctx = ctx; > > > + > > > + crtc_state = intel_atomic_get_crtc_state(state, crtc); > > > + if (IS_ERR(crtc_state)) { > > > + drm_atomic_state_free(state); > > > + state = NULL; > > > + } > > All this function does is call intel_atomic_get_crtc_state(). Since the > > caller > > also have to deal with error handling, I don't see what it adds on top of > > that. > > The code is actually simpler if merged with the function below. > This function needs to be called from two places. One in the commit() below, > and the other in the upfront_link_train() itself, when the crtc is not > enabled already. > > > > > > > > > > > + > > > + return crtc_state; > > > +} > > > + > > > +static int intel_dp_upfront_commit(struct intel_crtc *crtc, > > > + struct drm_modeset_acquire_ctx *ctx) > > This function could use a better name. Something that suggests the crtc is > > being disabled. Maybe disable_crtc_for_upfront() ? It doens't really depends > > on > Sure, better name makes sense.. > > > > > anything DP specific, so maybe it would make sense to move it to > > intel_display.c or intel_atomic.c. Then we could call it > > intel_crtc_atomic_disable_locked(). > > The "locked" part since this assumes the ctx already have crtc->mutex locked > > so > > that there's no risk of -EDEADLK. Although it can just pass the -EDEADLK > > error to > > the caller, so just intel_crtc_atomic_disable() ? > Still this would need to call the above get_crtc_state(..) function. > So, I will re-name and if it all looks Ok, will move it to atomic.c > Otherwise, will keep it here.. > > > > > > > > > > > > > > > +{ > > > + int ret; > > > + struct intel_crtc_state *crtc_state; > > > + enum pipe pipe = crtc->pipe; > > > + > > > + crtc_state = intel_dp_upfront_get_crtc_state(crtc, ctx); > > > + if (IS_ERR(crtc_state)) > > > + return PTR_ERR(crtc_state); > > > + > > > + DRM_DEBUG_KMS("Disabling crtc %c for upfront link train\n", > > > pipe_name(pipe)); > > > + > > > + crtc_state->base.active = false; > > > + ret = drm_atomic_commit(crtc_state->base.state); > > > + if (ret) { > > > + drm_atomic_state_free(crtc_state->base.state); > > > + crtc_state->base.state = NULL; > > The function drm_atomic_state_free() frees the crtc_state, so this is a use > > after free. > Will fix this.. > > > > > > > > > > > + } > > > + return ret; > > > +} > > > + > > > +static int intel_dp_upfront_link_train(struct drm_connector *connector) > > > +{ > > > + struct intel_dp *intel_dp = intel_attached_dp(connector); > > You could just pass intel_dp directly. The only use of connector is when > > connector->state->crtc is inspected. But that should have the same value as > > intel_dp->base.base.crtc > Ok, will change. > > > > > > > > > > > + struct intel_digital_port *intel_dig_port = > > > dp_to_dig_port(intel_dp); > > > + struct intel_encoder *intel_encoder = &intel_dig_port->base; > > > + struct drm_device *dev = intel_encoder->base.dev; > > > + struct drm_mode_config *config = &dev->mode_config; > > > + struct drm_modeset_acquire_ctx ctx; > > > + struct intel_crtc_state *crtc_state, *tmp_crtc_config; > > > + struct intel_crtc *intel_crtc; > > > + struct drm_crtc *crtc = NULL; > > > + bool crtc_enabled = false; > > > + int ret, status = 0; > > > + > > > + if (!IS_BROXTON(dev)) > > > + return 0; > > > + > > > + drm_modeset_acquire_init(&ctx, 0); > > > +retry: > > > + ret = drm_modeset_lock(&config->connection_mutex, &ctx); > > > + if (ret) > > > + goto exit_fail; > > > + > > > + if (connector->state->crtc) { > > > + crtc = connector->state->crtc; > > > + > > > + ret = drm_modeset_lock(&crtc->mutex, &ctx); > > > + if (ret) > > > + goto exit_fail; > > > + > > > + crtc_enabled = true; > > > + } else { > > > + crtc = intel_get_unused_crtc(&intel_encoder->base, &ctx); > > > + if (IS_ERR_OR_NULL(crtc)) { > > > + ret = PTR_ERR_OR_ZERO(crtc); > > > + DRM_DEBUG_KMS("No crtc available for upfront link > > > train:%d\n", ret); > > > + goto exit_fail; > > > + } > > > + intel_encoder->base.crtc = crtc; > > > + } > > IMO, the following would be a bit more readable. > > > > if (intel_encoder->base.crtc) > > crtc = intel_encoder->base.crtc; > > else > > crtc = intel_get_unused_crtc(&intel_encoder->base, &ctx); > > > > if (IS_ERR(crtc)) { > > ... > > } > > > > ret = drm_modeset_lock(&crtc->mutex, &ctx); > > if (ret) > > goto exit_fail; > > > > crtc_enabled = crtc->config->active; > > > Ok, makes sense. Will re-order this way. > > > > > > > > > + > > > + intel_crtc = to_intel_crtc(crtc); > > > + DRM_DEBUG_KMS("Using pipe %c for upfront link training\n", > > > + pipe_name(intel_crtc->pipe)); > > > + > > > + ret = drm_modeset_lock(&crtc->primary->mutex, &ctx); > > > + if (ret) > > > + goto exit_fail; > > > + > > > + if (crtc_enabled) { > > > + ret = intel_dp_upfront_commit(intel_crtc, &ctx); > > > + if (ret) > > > + goto exit_fail; > > > + } > > > + > > > + crtc_state = intel_dp_upfront_get_crtc_state(intel_crtc, &ctx); > > > + if (IS_ERR(crtc_state)) { > > > + ret = PTR_ERR(crtc_state); > > > + goto exit_fail; > > > + } > > > + > > > + /* Save the existing config */ > > > + tmp_crtc_config = intel_crtc->config; > > You need to save this earlier. Otherwise if intel_dp_upfront_commit() is > > called, the state will be restored with active == false when it should > > actually be true. > Ok, will save this earlier. But since we don’t re-enable crtc here after > upfront, > (we let it get re-enabled as part of subsequent modeset) the restoring > with false does not happen today.. > > > > > But that would cause intel_crtc->config to be freed, so you need to > > use intel_crtc_duplicate_state(). > Since we alloc a new state and then only call get_crtc_state(), I thought that > automatically boils down to duplicate_state() inside > drm_atomic_get_crtc_state(). > Please correct if my understanding is wrong. It does, but it is a somewhat messy way of doing it in this case, since you need to allocate an extra atomic_state. In any case, after looking at why we need to fiddle with the crtc_state, my conclusion was that it is easier to remove those dependencies than to do this save/restore dance. All it would take is to pass link rate and lane count directly to intel_dp_set_link_params(). The bulk of intel_ddi_pre_enable() can be split to a function that takes link rate, lane count and dpll as arguments, and then intel_bxt_upfront_link_train() can call it directly. > > > > > > > > > > > + intel_crtc->config = crtc_state; > > > + > > > + if (IS_BROXTON(dev)) > > > + status = intel_bxt_upfront_link_train(intel_dp, > > > intel_crtc); > > > + /* Other platforms upfront link train call goes here..*/ > > > + > > > + /* Restore the saved config */ > > > + intel_crtc->config = tmp_crtc_config; > > > + intel_encoder->base.crtc = crtc_enabled ? crtc : NULL; > > > + drm_atomic_state_free(crtc_state->base.state); > > This doesn't actually re-enables the crtc if if was disabled in > > intel_dp_upfront_commit(). This will require another atomic operation. > > Maybe that intel_crtc_atomic_disable() should just take a bool specifying if > > it > > should on of off. > We let it get re-enabled as part of mode set that happens subsequently. > Please let me know your opinion on this. There's no guarantee there will be a mode set afterwards, since that's a user space decision. One thing to check is if this works across suspend/resume. IIUC, it is possible a hotplug event won't be sent to user space if the connector status didn't change. In that case, I think this might lead to blank screen. Ander > > Thanks, > Durga > > > > > > > > > > > > > + > > > +exit_fail: > > > + if (ret == -EDEADLK) { > > > + drm_modeset_backoff(&ctx); > > > + goto retry; > > > + } > > > + drm_modeset_drop_locks(&ctx); > > > + drm_modeset_acquire_fini(&ctx); > > > + return status; > > > +} > > > + > > > static void > > > intel_dp_long_pulse(struct intel_connector *intel_connector) > > > { > > > @@ -4558,7 +4722,7 @@ intel_dp_long_pulse(struct intel_connector > > > *intel_connector) > > > struct drm_device *dev = connector->dev; > > > enum drm_connector_status status; > > > enum intel_display_power_domain power_domain; > > > - bool ret; > > > + bool ret, do_upfront_link_train; > > > u8 sink_irq_vector; > > > > > > power_domain = > > intel_display_port_aux_power_domain(intel_encoder); > > > > > > @@ -4604,7 +4768,11 @@ intel_dp_long_pulse(struct intel_connector > > > *intel_connector) > > > drm_modeset_lock(&dev- > > > mode_config.connection_mutex, NULL); > > > intel_dp_check_link_status(intel_dp); > > > drm_modeset_unlock(&dev- > > > mode_config.connection_mutex); > > > - goto out; > > > + /* > > > + * If we are here, we have (re)read DPCD above and hence > > > + * need to do upfront link train again. > > > + */ > > > + goto upfront; > > We can avoid this by not overwriting intel_dp->dpcd as I mentioned above. > > > > > > Ander > > > > > > > > } > > > > > > /* > > > @@ -4634,6 +4802,14 @@ intel_dp_long_pulse(struct intel_connector > > > *intel_connector) > > > DRM_DEBUG_DRIVER("CP or sink specific irq > > > unhandled\n"); > > > } > > > > > > +upfront: > > > + /* Do not do upfront link train, if it is a compliance request */ > > > + do_upfront_link_train = > > > + intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT && > > > + intel_dp->compliance_test_type != > > DP_TEST_LINK_TRAINING; > > > > > > + > > > + if (do_upfront_link_train && > > intel_dp_upfront_link_train(connector)) > > > > > > + status = connector_status_disconnected; > > > out: > > > if (status != connector_status_connected) { > > > intel_dp_unset_edid(intel_dp); > > > diff --git a/drivers/gpu/drm/i915/intel_drv.h > > > b/drivers/gpu/drm/i915/intel_drv.h > > > index 27b5dcd..bf98473 100644 > > > --- a/drivers/gpu/drm/i915/intel_drv.h > > > +++ b/drivers/gpu/drm/i915/intel_drv.h > > > @@ -1082,6 +1082,8 @@ void intel_ddi_clock_get(struct intel_encoder > > *encoder, > > > > > > struct intel_crtc_state *pipe_config); > > > void intel_ddi_set_vc_payload_alloc(struct drm_crtc *crtc, bool state); > > > uint32_t ddi_signal_levels(struct intel_dp *intel_dp); > > > +int intel_bxt_upfront_link_train(struct intel_dp *intel_dp, > > > + struct intel_crtc *crtc); > > > > > > /* intel_frontbuffer.c */ > > > void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj, > > > @@ -1284,6 +1286,9 @@ bool intel_dp_init_connector(struct > > intel_digital_port > > > > > > *intel_dig_port, > > > struct intel_connector *intel_connector); > > > void intel_dp_set_link_params(struct intel_dp *intel_dp, > > > const struct intel_crtc_state > > > *pipe_config); > > > +void intel_dp_update_dpcd_params(struct intel_dp *intel_dp); > > > +bool intel_dp_get_link_retry_params(struct intel_dp *intel_dp, > > > + uint8_t *lane_count, uint8_t *link_bw); > > > void intel_dp_start_link_train(struct intel_dp *intel_dp); > > > void intel_dp_stop_link_train(struct intel_dp *intel_dp); > > > void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode); _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
