From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pidgin.makrotopia.org (pidgin.makrotopia.org [185.142.180.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CE45F47010D for ; Wed, 22 Jul 2026 15:45:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.142.180.65 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784735157; cv=none; b=iwNWnCfwe09yHRF1HQSB4lzUWoDCAsVa86KA9zZMuiFVnCC+neiaDfZnPG4AtiCX5X0EltA7+Ziq8MkQ8Qy6EO1zRygNRgMZjSDT2VmXaq3zcwzKTnhTdu6GwlkdZjfAqgw6+VzqTUeqFbOFZPbcxX+HtKn+tawdz8kDsLFjgl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784735157; c=relaxed/simple; bh=965+uUTmKb3CgKlzi4aiAEp8NlQVeVxEKGf9MMlETw4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TAWkaCOrak7RSQupwo7m4JEjAlODAyQ68Y7ppSji/OS1NnWemBecDW7xHEt7BX/K0Bv06X4kyG5VjBA+Yvjox28I9UEIoFkAy1+bBv2Gw2qb1hGGDlnFOTgzltDcxGxn3c24tdiRXeZaRnT5kGUZ6fjeoASTFOXIGwrXC4p16J0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org; spf=pass smtp.mailfrom=makrotopia.org; arc=none smtp.client-ip=185.142.180.65 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=makrotopia.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=makrotopia.org Received: from local by pidgin.makrotopia.org with esmtpsa (TLS1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.99) (envelope-from ) id 1wmZ8d-000000006aS-3nj8; Wed, 22 Jul 2026 15:45:40 +0000 Date: Wed, 22 Jul 2026 16:45:36 +0100 From: Daniel Golle To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Matthias Brugger , AngeloGioacchino Del Regno , Hermes Wu , Allen Chen , Pin-yen Lin , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org Cc: Chen-Yu Tsai Subject: [PATCH v5 01/11] drm/bridge: it6505: quiesce event sources and work on remove() Message-ID: <837efb37cc967fc0bb4371d1051dd33838425d2d.1784717129.git.daniel@makrotopia.org> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: struct it6505 is freed by devres right after remove() returns, but remove() cancels none of the driver's work items, so link_works, hdcp_wait_ksv_list, hdcp_work and extcon_wq can still run afterwards and dereference freed memory. Cancelling alone would not be enough: the threaded IRQ and the extcon notifier stay live until devres teardown and can requeue the works. Unregister the extcon notifier and disable the IRQ first, then cancel all work. Make it6505_remove_notifier_module() idempotent, tracking registration in event_nb.notifier_call under extcon_lock, as both .detach() and remove() call it now. Also initialise extcon_wq in probe: cancel_work_sync() on a never-initialised work item trips WARN_ON(!work->func). Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver") Signed-off-by: Daniel Golle --- v5: serialise notifier registration state with extcon_lock v4: * quiesce event sources before cancelling work; retitled * initialise extcon_wq in probe to avoid WARN_ON(!work->func) v3: new patch drivers/gpu/drm/bridge/ite-it6505.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c index 8ecb43611dba..e9c84e4fb3a0 100644 --- a/drivers/gpu/drm/bridge/ite-it6505.c +++ b/drivers/gpu/drm/bridge/ite-it6505.c @@ -2934,15 +2934,18 @@ static int it6505_use_notifier_module(struct it6505 *it6505) int ret; struct device *dev = it6505->dev; + mutex_lock(&it6505->extcon_lock); it6505->event_nb.notifier_call = it6505_extcon_notifier; - INIT_WORK(&it6505->extcon_wq, it6505_extcon_work); ret = devm_extcon_register_notifier(it6505->dev, it6505->extcon, EXTCON_DISP_DP, &it6505->event_nb); if (ret) { + it6505->event_nb.notifier_call = NULL; + mutex_unlock(&it6505->extcon_lock); dev_err(dev, "failed to register notifier for DP"); return ret; } + mutex_unlock(&it6505->extcon_lock); schedule_work(&it6505->extcon_wq); @@ -2951,13 +2954,16 @@ static int it6505_use_notifier_module(struct it6505 *it6505) static void it6505_remove_notifier_module(struct it6505 *it6505) { - if (it6505->extcon) { - devm_extcon_unregister_notifier(it6505->dev, - it6505->extcon, EXTCON_DISP_DP, + mutex_lock(&it6505->extcon_lock); + if (it6505->extcon && it6505->event_nb.notifier_call) { + devm_extcon_unregister_notifier(it6505->dev, it6505->extcon, + EXTCON_DISP_DP, &it6505->event_nb); - - flush_work(&it6505->extcon_wq); + it6505->event_nb.notifier_call = NULL; } + mutex_unlock(&it6505->extcon_lock); + + flush_work(&it6505->extcon_wq); } static void __maybe_unused it6505_delayed_audio(struct work_struct *work) @@ -3615,6 +3621,7 @@ static int it6505_i2c_probe(struct i2c_client *client) INIT_WORK(&it6505->link_works, it6505_link_training_work); INIT_WORK(&it6505->hdcp_wait_ksv_list, it6505_hdcp_wait_ksv_list); INIT_DELAYED_WORK(&it6505->hdcp_work, it6505_hdcp_work); + INIT_WORK(&it6505->extcon_wq, it6505_extcon_work); init_completion(&it6505->extcon_completion); memset(it6505->dpcd, 0, sizeof(it6505->dpcd)); it6505->powered = false; @@ -3647,6 +3654,12 @@ static void it6505_i2c_remove(struct i2c_client *client) drm_bridge_remove(&it6505->bridge); drm_dp_aux_unregister(&it6505->aux); it6505_debugfs_remove(it6505); + it6505_remove_notifier_module(it6505); + disable_irq(it6505->irq); + cancel_work_sync(&it6505->link_works); + cancel_work_sync(&it6505->hdcp_wait_ksv_list); + cancel_delayed_work_sync(&it6505->hdcp_work); + cancel_work_sync(&it6505->extcon_wq); it6505_poweroff(it6505); it6505_remove_edid(it6505); } -- 2.55.0