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bh=4uLJEtoS2PPJFMr0I1tAyocsm8P41/TMCB7vqODm0mU=; b=OoZpBxZVH/MaCQGmcz4JeZqJ48Oqd3LrSrTxiEnH0uO9644BdWBqRtn6n0Po58+Fu4amN0 9bPks+EnjQIvq3wD4XxW2cxFKbMsDIWEwkA909n5rmpr5Ei5RIBdaZU7GUexzRQJ/J3AWG BH6BimoOaVQNFxGTsv1m65LeCDF+0G5FxUDq2+y034cUmUMlXrKLTEmWrFlme3eC1e0Ehp B5L1IHtZJXS/dBqZrIhdaSO4RJH4ssqOZKO4GOgub9I1Uv5PB5R4Ni5M5dUMHaoODFaCgo V6EEHxvUY9E8hGGTmHW6JHt0DXkS+ATUCf46+WzfEd2xk9r4TLw+hK1/HWQPeQ== Date: Fri, 7 Feb 2025 14:30:03 +0100 From: Herve Codina To: Lee Jones , Daniel Thompson , Jingoo Han , Helge Deller , Tony Lindgren , Pavel Machek , Tomi Valkeinen , Jean-Jacques Hiblot Cc: Daniel Thompson , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Ceresoli , Thomas Petazzoni , stable@vger.kernel.org Subject: Re: [PATCH] backlight: led_bl: Hold led_access lock when calling led_sysfs_disable() Message-ID: <20250207143003.1c518df3@bootlin.com> In-Reply-To: <20250122091914.309533-1-herve.codina@bootlin.com> References: <20250122091914.309533-1-herve.codina@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddvleegtdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkjghfohfogggtgfesthekredtredtjeenucfhrhhomhepjfgvrhhvvgcuvehoughinhgruceohhgvrhhvvgdrtghoughinhgrsegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeviefffeegiedtleelieeghfejleeuueevkeevteegffehledtkeegudeigffgvdenucfkphepledtrdekledrudeifedruddvjeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeeltddrkeelrdduieefrdduvdejpdhhvghloheplhhotggrlhhhohhsthdpmhgrihhlfhhrohhmpehhvghrvhgvrdgtohguihhnrgessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepudehpdhrtghpthhtoheplhgvvgeskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepuggrnhhivghltheskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepjhhinhhgohhohhgrnhdusehgmhgrihhlrdgtohhmpdhrtghpthhtohepuggvlhhlvghrsehgmhigrdguvgdprhgtphhtthhopehtohhnhiesrghtohhmihguvgdrtghomhdprhgtphhtthhopehprghvvghlsehutgifrdgtiidprhgtphhtthhopehtohhmi hdrvhgrlhhkvghinhgvnhesthhirdgtohhmpdhrtghpthhtohepjhhjhhhisghlohhtsehtihdrtghomh X-GND-Sasl: herve.codina@bootlin.com Hi Lee, Daniel, Jingoo, On Wed, 22 Jan 2025 10:19:14 +0100 Herve Codina wrote: > Lockdep detects the following issue on led-backlight removal: > [ 142.315935] ------------[ cut here ]------------ > [ 142.315954] WARNING: CPU: 2 PID: 292 at drivers/leds/led-core.c:455 led_sysfs_enable+0x54/0x80 > ... > [ 142.500725] Call trace: > [ 142.503176] led_sysfs_enable+0x54/0x80 (P) > [ 142.507370] led_bl_remove+0x80/0xa8 [led_bl] > [ 142.511742] platform_remove+0x30/0x58 > [ 142.515501] device_remove+0x54/0x90 > ... > > Indeed, led_sysfs_enable() has to be called with the led_access > lock held. > > Hold the lock when calling led_sysfs_disable(). > > Fixes: ae232e45acf9 ("backlight: add led-backlight driver") > Cc: stable@vger.kernel.org > Signed-off-by: Herve Codina I didn't receive any feedback. v6.14-rc1 has been released since the patch was sent but the patch applies on top of v6.14-rc1 without any issue. Of course if really needed, I can resend the patch. Just tell me. Best regards, Hervé