From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 57989C5DF81 for ; Tue, 18 Aug 2026 08:37:58 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5CFDB10EA6B; Tue, 18 Aug 2026 08:37:57 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="Eg4v5As3"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8E07D10E29C; Tue, 18 Aug 2026 08:37:55 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 7A9C2601FB; Tue, 18 Aug 2026 08:37:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30C2B1F000E9; Tue, 18 Aug 2026 08:37:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787042274; bh=UWOItxshjgunutowy4O4GM5w0tL4xTShpPtcGHO8dpI=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Eg4v5As3JImBNdvq/sy+ojWBL8t1/NW2eHOE8BBo9uONA+8i734cdQvdkx+8M1qBz VnyJFh8HLBqI8svLslKz63fNPLJ4nzSY7TaBXU3EyKpteLwW+LbFlxoUOtm4ya+PJX KveJIj9HBv3fjaMYH95Fac3yCVJ8JT3c18tZ/2+wDtOZ+pjIWa2YFLoreQ7+wjOaQe /4U+mTELzo1jRoYLwz3TAAybGWToz2u5inSfEIebifnpW11UqYdR9mPZZEqZl5atoC /499MNE3tCfVZq0eHBn7DJNBKoBvRL/L12skhHJNUd5I1iJ63FUkgYtnYoB7KSYVre EL1uOwmzj91Cw== Received: from johan by xi.lan with local (Exim 4.99.4) (envelope-from ) id 1wwFKR-00000000nYZ-3y4R; Tue, 18 Aug 2026 10:37:51 +0200 Date: Tue, 18 Aug 2026 10:37:51 +0200 From: Johan Hovold To: Guangshuo Li Cc: Lucas Stach , Russell King , Christian Gmeiner , David Airlie , Simona Vetter , etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] drm/etnaviv: fix runtime PM cleanup during teardown Message-ID: References: <20260808121434.2815841-1-lgs201920130244@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260808121434.2815841-1-lgs201920130244@gmail.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Sat, Aug 08, 2026 at 08:14:34PM +0800, Guangshuo Li wrote: > etnaviv_gpu_platform_probe() calls pm_runtime_use_autosuspend() and > enables runtime PM before registering the component. If component_add() > fails, the probe path returns without undoing the autosuspend setting > or disabling runtime PM. The remove path also disables runtime PM > without calling the matching pm_runtime_dont_use_autosuspend(). > > If the autosuspend delay is set to a negative value while autosuspend > is enabled, the runtime PM core increments usage_count to prevent > runtime suspend. Without calling pm_runtime_dont_use_autosuspend() > during teardown, this reference is not dropped and usage_count remains > unbalanced. As I've explained elsewhere, this is just misleading. There is no usage count leak here as the count is balanced whenever the user re-enables autosuspend through sysfs (by writing a non-negative timeout). Drivers should clean up after themselves and disable autosuspend, but this is more of a clean up than a fix and should not be backported. You've sent upwards of 60 of these in the matter of a just a few days, some which have even been picked up. Please send follow-ups (replies or v2s) as soon as possible to prevent further of these from getting merged. > The documentation for pm_runtime_use_autosuspend() also notes that it > is important to undo it with pm_runtime_dont_use_autosuspend() at > driver exit time, unless runtime PM was initially enabled with > devm_pm_runtime_enable(). > > Undo the autosuspend setting on both probe failure and device removal, > and disable runtime PM on the component registration failure path. > > This issue was found by manual code inspection. > > Fixes: a8c21a5451d8 ("drm/etnaviv: add initial etnaviv DRM driver") > Cc: stable@vger.kernel.org > Signed-off-by: Guangshuo Li Johan