From 05193dc38197021894b17239fafbd2eb1afe5a45 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Tue, 3 Dec 2019 15:15:08 +0100 Subject: [PATCH] drm/bridge: Make the bridge chain a double-linked list So that each element in the chain can easily access its predecessor. This will be needed to support bus format negotiation between elements of the bridge chain. Signed-off-by: Boris Brezillon Reviewed-by: Neil Armstrong Reviewed-by: Laurent Pinchart Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-5-boris.brezillon@collabora.com --- drivers/gpu/drm/drm_bridge.c | 171 +++++++++++++++--------- drivers/gpu/drm/drm_encoder.c | 16 +-- drivers/gpu/drm/exynos/exynos_drm_dsi.c | 5 +- drivers/gpu/drm/vc4/vc4_dsi.c | 10 +- include/drm/drm_bridge.h | 12 +- include/drm/drm_encoder.h | 7 +- 6 files changed, 143 insertions(+), 78 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 54c874493c57..b6517b4fa3d1 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -55,7 +55,7 @@ * just provide additional hooks to get the desired output at the end of the * encoder chain. * - * Bridges can also be chained up using the &drm_bridge.next pointer. + * Bridges can also be chained up using the &drm_bridge.chain_node field. * * Both legacy CRTC helpers and the new atomic modeset helpers support bridges. */ @@ -128,20 +128,21 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, bridge->dev = encoder->dev; bridge->encoder = encoder; + if (previous) + list_add(&bridge->chain_node, &previous->chain_node); + else + list_add(&bridge->chain_node, &encoder->bridge_chain); + if (bridge->funcs->attach) { ret = bridge->funcs->attach(bridge); if (ret < 0) { + list_del(&bridge->chain_node); bridge->dev = NULL; bridge->encoder = NULL; return ret; } } - if (previous) - previous->next = bridge; - else - encoder->bridge = bridge; - return 0; } EXPORT_SYMBOL(drm_bridge_attach); @@ -157,6 +158,7 @@ void drm_bridge_detach(struct drm_bridge *bridge) if (bridge->funcs->detach) bridge->funcs->detach(bridge); + list_del(&bridge->chain_node); bridge->dev = NULL; } @@ -190,18 +192,21 @@ bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge, const struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode) { - bool ret = true; + struct drm_encoder *encoder; if (!bridge) return true; - if (bridge->funcs->mode_fixup) - ret = bridge->funcs->mode_fixup(bridge, mode, adjusted_mode); + encoder = bridge->encoder; + list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + if (!bridge->funcs->mode_fixup) + continue; - ret = ret && drm_bridge_chain_mode_fixup(bridge->next, mode, - adjusted_mode); + if (!bridge->funcs->mode_fixup(bridge, mode, adjusted_mode)) + return false; + } - return ret; + return true; } EXPORT_SYMBOL(drm_bridge_chain_mode_fixup); @@ -224,18 +229,24 @@ enum drm_mode_status drm_bridge_chain_mode_valid(struct drm_bridge *bridge, const struct drm_display_mode *mode) { - enum drm_mode_status ret = MODE_OK; + struct drm_encoder *encoder; if (!bridge) - return ret; + return MODE_OK; - if (bridge->funcs->mode_valid) - ret = bridge->funcs->mode_valid(bridge, mode); + encoder = bridge->encoder; + list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + enum drm_mode_status ret; + + if (!bridge->funcs->mode_valid) + continue; - if (ret != MODE_OK) - return ret; + ret = bridge->funcs->mode_valid(bridge, mode); + if (ret != MODE_OK) + return ret; + } - return drm_bridge_chain_mode_valid(bridge->next, mode); + return MODE_OK; } EXPORT_SYMBOL(drm_bridge_chain_mode_valid); @@ -251,13 +262,20 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_valid); */ void drm_bridge_chain_disable(struct drm_bridge *bridge) { + struct drm_encoder *encoder; + struct drm_bridge *iter; + if (!bridge) return; - drm_bridge_chain_disable(bridge->next); + encoder = bridge->encoder; + list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { + if (iter->funcs->disable) + iter->funcs->disable(iter); - if (bridge->funcs->disable) - bridge->funcs->disable(bridge); + if (iter == bridge) + break; + } } EXPORT_SYMBOL(drm_bridge_chain_disable); @@ -274,13 +292,16 @@ EXPORT_SYMBOL(drm_bridge_chain_disable); */ void drm_bridge_chain_post_disable(struct drm_bridge *bridge) { + struct drm_encoder *encoder; + if (!bridge) return; - if (bridge->funcs->post_disable) - bridge->funcs->post_disable(bridge); - - drm_bridge_chain_post_disable(bridge->next); + encoder = bridge->encoder; + list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + if (bridge->funcs->post_disable) + bridge->funcs->post_disable(bridge); + } } EXPORT_SYMBOL(drm_bridge_chain_post_disable); @@ -300,13 +321,16 @@ void drm_bridge_chain_mode_set(struct drm_bridge *bridge, const struct drm_display_mode *mode, const struct drm_display_mode *adjusted_mode) { + struct drm_encoder *encoder; + if (!bridge) return; - if (bridge->funcs->mode_set) - bridge->funcs->mode_set(bridge, mode, adjusted_mode); - - drm_bridge_chain_mode_set(bridge->next, mode, adjusted_mode); + encoder = bridge->encoder; + list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + if (bridge->funcs->mode_set) + bridge->funcs->mode_set(bridge, mode, adjusted_mode); + } } EXPORT_SYMBOL(drm_bridge_chain_mode_set); @@ -323,13 +347,17 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_set); */ void drm_bridge_chain_pre_enable(struct drm_bridge *bridge) { + struct drm_encoder *encoder; + struct drm_bridge *iter; + if (!bridge) return; - drm_bridge_chain_pre_enable(bridge->next); - - if (bridge->funcs->pre_enable) - bridge->funcs->pre_enable(bridge); + encoder = bridge->encoder; + list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { + if (iter->funcs->pre_enable) + iter->funcs->pre_enable(iter); + } } EXPORT_SYMBOL(drm_bridge_chain_pre_enable); @@ -345,13 +373,16 @@ EXPORT_SYMBOL(drm_bridge_chain_pre_enable); */ void drm_bridge_chain_enable(struct drm_bridge *bridge) { + struct drm_encoder *encoder; + if (!bridge) return; - if (bridge->funcs->enable) - bridge->funcs->enable(bridge); - - drm_bridge_chain_enable(bridge->next); + encoder = bridge->encoder; + list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + if (bridge->funcs->enable) + bridge->funcs->enable(bridge); + } } EXPORT_SYMBOL(drm_bridge_chain_enable); @@ -370,15 +401,22 @@ EXPORT_SYMBOL(drm_bridge_chain_enable); void drm_atomic_bridge_chain_disable(struct drm_bridge *bridge, struct drm_atomic_state *state) { + struct drm_encoder *encoder; + struct drm_bridge *iter; + if (!bridge) return; - drm_atomic_bridge_chain_disable(bridge->next, state); + encoder = bridge->encoder; + list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { + if (iter->funcs->atomic_disable) + iter->funcs->atomic_disable(iter, state); + else if (iter->funcs->disable) + iter->funcs->disable(iter); - if (bridge->funcs->atomic_disable) - bridge->funcs->atomic_disable(bridge, state); - else if (bridge->funcs->disable) - bridge->funcs->disable(bridge); + if (iter == bridge) + break; + } } EXPORT_SYMBOL(drm_atomic_bridge_chain_disable); @@ -398,15 +436,18 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_disable); void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge, struct drm_atomic_state *state) { + struct drm_encoder *encoder; + if (!bridge) return; - if (bridge->funcs->atomic_post_disable) - bridge->funcs->atomic_post_disable(bridge, state); - else if (bridge->funcs->post_disable) - bridge->funcs->post_disable(bridge); - - drm_atomic_bridge_chain_post_disable(bridge->next, state); + encoder = bridge->encoder; + list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + if (bridge->funcs->atomic_post_disable) + bridge->funcs->atomic_post_disable(bridge, state); + else if (bridge->funcs->post_disable) + bridge->funcs->post_disable(bridge); + } } EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable); @@ -426,15 +467,22 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_post_disable); void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge, struct drm_atomic_state *state) { + struct drm_encoder *encoder; + struct drm_bridge *iter; + if (!bridge) return; - drm_atomic_bridge_chain_pre_enable(bridge->next, state); + encoder = bridge->encoder; + list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) { + if (iter->funcs->atomic_pre_enable) + iter->funcs->atomic_pre_enable(iter, state); + else if (iter->funcs->pre_enable) + iter->funcs->pre_enable(iter); - if (bridge->funcs->atomic_pre_enable) - bridge->funcs->atomic_pre_enable(bridge, state); - else if (bridge->funcs->pre_enable) - bridge->funcs->pre_enable(bridge); + if (iter == bridge) + break; + } } EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable); @@ -453,15 +501,18 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable); void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge, struct drm_atomic_state *state) { + struct drm_encoder *encoder; + if (!bridge) return; - if (bridge->funcs->atomic_enable) - bridge->funcs->atomic_enable(bridge, state); - else if (bridge->funcs->enable) - bridge->funcs->enable(bridge); - - drm_atomic_bridge_chain_enable(bridge->next, state); + encoder = bridge->encoder; + list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + if (bridge->funcs->atomic_enable) + bridge->funcs->atomic_enable(bridge, state); + else if (bridge->funcs->enable) + bridge->funcs->enable(bridge); + } } EXPORT_SYMBOL(drm_atomic_bridge_chain_enable); diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c index a2cc7e7241a9..e555281f43d4 100644 --- a/drivers/gpu/drm/drm_encoder.c +++ b/drivers/gpu/drm/drm_encoder.c @@ -140,6 +140,7 @@ int drm_encoder_init(struct drm_device *dev, goto out_put; } + INIT_LIST_HEAD(&encoder->bridge_chain); list_add_tail(&encoder->head, &dev->mode_config.encoder_list); encoder->index = dev->mode_config.num_encoder++; @@ -160,23 +161,16 @@ EXPORT_SYMBOL(drm_encoder_init); void drm_encoder_cleanup(struct drm_encoder *encoder) { struct drm_device *dev = encoder->dev; + struct drm_bridge *bridge, *next; /* Note that the encoder_list is considered to be static; should we * remove the drm_encoder at runtime we would have to decrement all * the indices on the drm_encoder after us in the encoder_list. */ - if (encoder->bridge) { - struct drm_bridge *bridge; - struct drm_bridge *next; - - bridge = drm_bridge_chain_get_first_bridge(encoder); - while (bridge) { - next = drm_bridge_get_next_bridge(bridge); - drm_bridge_detach(bridge); - bridge = next; - } - } + list_for_each_entry_safe(bridge, next, &encoder->bridge_chain, + chain_node) + drm_bridge_detach(bridge); drm_mode_object_unregister(dev, &encoder->base); kfree(encoder->name); diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c index d984097704b8..7de82e22252a 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c @@ -255,6 +255,7 @@ struct exynos_dsi { struct mipi_dsi_host dsi_host; struct drm_connector connector; struct drm_panel *panel; + struct list_head bridge_chain; struct drm_bridge *out_bridge; struct device *dev; @@ -1522,7 +1523,7 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host, if (out_bridge) { drm_bridge_attach(encoder, out_bridge, NULL); dsi->out_bridge = out_bridge; - encoder->bridge = NULL; + list_splice(&encoder->bridge_chain, &dsi->bridge_chain); } else { int ret = exynos_dsi_create_connector(encoder); @@ -1588,6 +1589,7 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host, if (dsi->out_bridge->funcs->detach) dsi->out_bridge->funcs->detach(dsi->out_bridge); dsi->out_bridge = NULL; + INIT_LIST_HEAD(&dsi->bridge_chain); } if (drm->mode_config.poll_enabled) @@ -1735,6 +1737,7 @@ static int exynos_dsi_probe(struct platform_device *pdev) init_completion(&dsi->completed); spin_lock_init(&dsi->transfer_lock); INIT_LIST_HEAD(&dsi->transfer_list); + INIT_LIST_HEAD(&dsi->bridge_chain); dsi->dsi_host.ops = &exynos_dsi_ops; dsi->dsi_host.dev = dev; diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index ff81b54ea281..6c5b80ad6154 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -499,6 +499,7 @@ struct vc4_dsi { struct mipi_dsi_host dsi_host; struct drm_encoder *encoder; struct drm_bridge *bridge; + struct list_head bridge_chain; void __iomem *regs; @@ -1460,6 +1461,8 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data) GFP_KERNEL); if (!vc4_dsi_encoder) return -ENOMEM; + + INIT_LIST_HEAD(&dsi->bridge_chain); vc4_dsi_encoder->base.type = VC4_ENCODER_TYPE_DSI1; vc4_dsi_encoder->dsi = dsi; dsi->encoder = &vc4_dsi_encoder->base.base; @@ -1610,7 +1613,7 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data) * from our driver, since we need to sequence them within the * encoder's enable/disable paths. */ - dsi->encoder->bridge = NULL; + list_splice(&dsi->encoder->bridge_chain, &dsi->bridge_chain); if (dsi->port == 0) vc4_debugfs_add_regset32(drm, "dsi0_regs", &dsi->regset); @@ -1632,6 +1635,11 @@ static void vc4_dsi_unbind(struct device *dev, struct device *master, if (dsi->bridge) pm_runtime_disable(dev); + /* + * Restore the bridge_chain so the bridge detach procedure can happen + * normally. + */ + list_splice(&dsi->bridge_chain, &dsi->encoder->bridge_chain); vc4_dsi_encoder_destroy(dsi->encoder); if (dsi->port == 1) diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index bd78c256b1ed..c118726469ee 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -384,8 +384,8 @@ struct drm_bridge { struct drm_device *dev; /** @encoder: encoder to which this bridge is connected */ struct drm_encoder *encoder; - /** @next: the next bridge in the encoder chain */ - struct drm_bridge *next; + /** @chain_node: used to form a bridge chain */ + struct list_head chain_node; #ifdef CONFIG_OF /** @of_node: device node pointer to the bridge */ struct device_node *of_node; @@ -420,7 +420,10 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, static inline struct drm_bridge * drm_bridge_get_next_bridge(struct drm_bridge *bridge) { - return bridge->next; + if (list_is_last(&bridge->chain_node, &bridge->encoder->bridge_chain)) + return NULL; + + return list_next_entry(bridge, chain_node); } /** @@ -434,7 +437,8 @@ drm_bridge_get_next_bridge(struct drm_bridge *bridge) static inline struct drm_bridge * drm_bridge_chain_get_first_bridge(struct drm_encoder *encoder) { - return encoder->bridge; + return list_first_entry_or_null(&encoder->bridge_chain, + struct drm_bridge, chain_node); } bool drm_bridge_chain_mode_fixup(struct drm_bridge *bridge, diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h index f06164f44efe..5623994b6e9e 100644 --- a/include/drm/drm_encoder.h +++ b/include/drm/drm_encoder.h @@ -172,7 +172,12 @@ struct drm_encoder { * &drm_connector_state.crtc. */ struct drm_crtc *crtc; - struct drm_bridge *bridge; + + /** + * @bridge_chain: Bridges attached to this encoder. + */ + struct list_head bridge_chain; + const struct drm_encoder_funcs *funcs; const struct drm_encoder_helper_funcs *helper_private; }; -- 2.30.2