From e13a058310509b22b2b45cbdd82d8797e173c3db Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 5 Jul 2017 06:56:29 +0200 Subject: [PATCH] drm/fb-helper: Stop using mode_config.mutex for internals Mime-version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 8bit Git-commit: e13a058310509b22b2b45cbdd82d8797e173c3db Patch-mainline: v4.14-rc1 References: FATE#322643 bsc#1055900 Those are now all protected using fb_helper->lock. V2: We still need to hold mode_config.mutex right around calling connector->fill_modes. V3: I forgot to hold mode_config.mutex while looking at connector->status and the mode list. Also, we need to patch up the i915 ->initial_config callback to grab the locks it needs to inspect the modeset state recovered from the fw. V4: Don't reorder the probe too much (Ville). Cc: Ville Syrjälä Cc: John Stultz Cc: Thierry Reding Reviewed-by: Maarten Lankhorst Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170705045629.31265-1-daniel.vetter@ffwll.ch Acked-by: Takashi Iwai --- drivers/gpu/drm/drm_fb_helper.c | 33 ++++++++------------------------- drivers/gpu/drm/drm_vblank.c | 2 +- drivers/gpu/drm/i915/intel_fbdev.c | 16 ++++++++++++---- 3 files changed, 21 insertions(+), 30 deletions(-) --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -106,7 +106,7 @@ static DEFINE_MUTEX(kernel_fb_helper_loc */ #define drm_fb_helper_for_each_connector(fbh, i__) \ - for (({ lockdep_assert_held(&(fbh)->dev->mode_config.mutex); }), \ + for (({ lockdep_assert_held(&(fbh)->lock); }), \ i__ = 0; i__ < (fbh)->connector_count; i__++) static int __drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, @@ -120,7 +120,6 @@ static int __drm_fb_helper_add_one_conne return 0; lockdep_assert_held(&fb_helper->lock); - lockdep_assert_held(&fb_helper->dev->mode_config.mutex); count = fb_helper->connector_count + 1; @@ -152,11 +151,7 @@ int drm_fb_helper_add_one_connector(stru int err; mutex_lock(&fb_helper->lock); - mutex_lock(&fb_helper->dev->mode_config.mutex); - err = __drm_fb_helper_add_one_connector(fb_helper, connector); - - mutex_unlock(&fb_helper->dev->mode_config.mutex); mutex_unlock(&fb_helper->lock); return err; @@ -188,7 +183,6 @@ int drm_fb_helper_single_add_all_connect return 0; mutex_lock(&fb_helper->lock); - mutex_lock(&dev->mode_config.mutex); drm_connector_list_iter_begin(dev, &conn_iter); drm_for_each_connector_iter(connector, &conn_iter) { ret = __drm_fb_helper_add_one_connector(fb_helper, connector); @@ -210,7 +204,6 @@ fail: fb_helper->connector_count = 0; out: drm_connector_list_iter_end(&conn_iter); - mutex_unlock(&dev->mode_config.mutex); mutex_unlock(&fb_helper->lock); return ret; @@ -253,11 +246,7 @@ int drm_fb_helper_remove_one_connector(s int err; mutex_lock(&fb_helper->lock); - mutex_lock(&fb_helper->dev->mode_config.mutex); - err = __drm_fb_helper_remove_one_connector(fb_helper, connector); - - mutex_unlock(&fb_helper->dev->mode_config.mutex); mutex_unlock(&fb_helper->lock); return err; @@ -1879,12 +1868,11 @@ void drm_fb_helper_fill_var(struct fb_in EXPORT_SYMBOL(drm_fb_helper_fill_var); static int drm_fb_helper_probe_connector_modes(struct drm_fb_helper *fb_helper, - uint32_t maxX, - uint32_t maxY) + uint32_t maxX, + uint32_t maxY) { struct drm_connector *connector; - int count = 0; - int i; + int i, count = 0; drm_fb_helper_for_each_connector(fb_helper, i) { connector = fb_helper->connector_info[i]->connector; @@ -2282,12 +2270,8 @@ static void drm_setup_crtcs(struct drm_f int i; DRM_DEBUG_KMS("\n"); - if (drm_fb_helper_probe_connector_modes(fb_helper, width, height) == 0) - DRM_DEBUG_KMS("No connectors reported connected with modes\n"); - /* prevent concurrent modification of connector_count by hotplug */ lockdep_assert_held(&fb_helper->lock); - lockdep_assert_held(&fb_helper->dev->mode_config.mutex); crtcs = kcalloc(fb_helper->connector_count, sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL); @@ -2302,6 +2286,9 @@ static void drm_setup_crtcs(struct drm_f goto out; } + mutex_lock(&fb_helper->dev->mode_config.mutex); + if (drm_fb_helper_probe_connector_modes(fb_helper, width, height) == 0) + DRM_DEBUG_KMS("No connectors reported connected with modes\n"); drm_enable_connectors(fb_helper, enabled); if (!(fb_helper->funcs->initial_config && @@ -2323,6 +2310,7 @@ static void drm_setup_crtcs(struct drm_f drm_pick_crtcs(fb_helper, crtcs, modes, 0, width, height); } + mutex_unlock(&fb_helper->dev->mode_config.mutex); /* need to set the modesets up here for use later */ /* fill out the connector<->crtc mappings into the modesets */ @@ -2414,12 +2402,10 @@ int drm_fb_helper_initial_config(struct return 0; mutex_lock(&fb_helper->lock); - mutex_lock(&dev->mode_config.mutex); drm_setup_crtcs(fb_helper, dev->mode_config.max_width, dev->mode_config.max_height); ret = drm_fb_helper_single_fb_probe(fb_helper, bpp_sel); - mutex_unlock(&dev->mode_config.mutex); mutex_unlock(&fb_helper->lock); if (ret) return ret; @@ -2482,10 +2468,7 @@ int drm_fb_helper_hotplug_event(struct d DRM_DEBUG_KMS("\n"); - mutex_lock(&dev->mode_config.mutex); drm_setup_crtcs(fb_helper, fb_helper->fb->width, fb_helper->fb->height); - - mutex_unlock(&dev->mode_config.mutex); mutex_unlock(&fb_helper->lock); drm_fb_helper_set_par(fb_helper->fbdev); --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -836,7 +836,7 @@ static void send_vblank_event(struct drm * NOTE: Drivers using this to send out the &drm_crtc_state.event as part of an * atomic commit must ensure that the next vblank happens at exactly the same * time as the atomic commit is committed to the hardware. This function itself - * does **not** protect again the next vblank interrupt racing with either this + * does **not** protect against the next vblank interrupt racing with either this * function call or the atomic commit operation. A possible sequence could be: * * 1. Driver commits new hardware state into vblank-synchronized registers. --- a/drivers/gpu/drm/i915/intel_fbdev.c +++ b/drivers/gpu/drm/i915/intel_fbdev.c @@ -352,14 +352,20 @@ static bool intel_fb_initial_config(stru unsigned int count = min(fb_helper->connector_count, BITS_PER_LONG); int i, j; bool *save_enabled; - bool fallback = true; + bool fallback = true, ret = true; int num_connectors_enabled = 0; int num_connectors_detected = 0; + struct drm_modeset_acquire_ctx ctx; save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL); if (!save_enabled) return false; + drm_modeset_acquire_init(&ctx, 0); + + while (drm_modeset_lock_all_ctx(fb_helper->dev, &ctx) != 0) + drm_modeset_backoff(&ctx); + memcpy(save_enabled, enabled, count); mask = GENMASK(count - 1, 0); conn_configured = 0; @@ -509,12 +515,14 @@ retry: bail: DRM_DEBUG_KMS("Not using firmware configuration\n"); memcpy(enabled, save_enabled, count); - kfree(save_enabled); - return false; + ret = false; } + drm_modeset_drop_locks(&ctx); + drm_modeset_acquire_fini(&ctx); + kfree(save_enabled); - return true; + return ret; } static const struct drm_fb_helper_funcs intel_fb_helper_funcs = {