From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794330106; b=nCgHrRG56jO1/kVe7WiJP2WW/20p/FN/5yDAL8McJRtt3G25Ev0HhLZ2Fi1DwEpDCBrb tDnM1tUHsitCt9YdGq0zNjCzVW4GI5INtxo6VrVcceHHko1ScZ/+qqm4bpufkie7Weqtd wTVct26A5HHAuFGNnwKTprc6r2MT6opPKYxgihEuL2uDUrZXLQ9WraOvS4XQprEGyWCQy 4uOTZVwilh7J/ObicCYdxbYZ3xd1bYjcFGPiOaw0+bl/KaiCrLjePtCVguBcqbgu0ntQm KMu4J4pXz/LxyiVeItPAX5oSTT4kr7YErM2jy0YymbnhQ2ilLLohTJikpBZ3uvYkCWg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794330106; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=ZEfJ+FoBZE/WPYeBgWFbac0JSzMWG12Id7xGOgbY0Tc=; b=lvSgbsUfwz8MCgxEsfz5UeLTEcxzAIyZUyoj5LBcSkWgSvqoW1M0+OotunZB5Ns18610 SSvO7WCf/2mOTjsKztFJYNZJuAWT81Htk9XY5h7xkfIfeZ/HD14MCN/+XZDvhGjKQKwik ci1A+hD01IkHh11XjVF3SI7UGWnGpukHoqChpUWyNaDhoWHBwVIGQXQtKqZve8GS36fVX 7lcIieWAqyPTyhksTXaUWgVPiqASn4latomR7gtTYVOGeTmexBEP6kPnfH+orEkPEGHk/ ObPUHFqYoKP3bX/MRQ9sgRn6p7O9WqNuZjkKUPGjyyUYsTA1diklL7a7blPMdJb7pmg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=QjyJr583; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8FE50606A321 for ; Tue, 10 Nov 2026 17:01:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=QjyJr583 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E0C21F0089F; Tue, 10 Nov 2026 17:01:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794330106; bh=ZEfJ+FoBZE/WPYeBgWFbac0JSzMWG12Id7xGOgbY0Tc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QjyJr583MbXWqFk5NEICoILgaQSK47orGBWFrKaG2QyUS7sdY7PM3Gpv5MdDDNPO+ MkXqxHXpbVGnmiERnFXPL7ZSpDZA6q5rzkhT85RrWUCVrmeh4W2bu+NXgu1oiAQudF PEr6SqKtepF84p19dPBmanb4Ov44+Yk8OEDi1eP9I7Wiwz93JHREYWDPGNF+E+zXN9 BImJVsadSj5ZjnpSU0Cx4P1SqPFJRMpcS7eCGkTsZolEsaFXLXCDg+S+m+UW3w7iLY MIJbF8bho8LbYLSk0DBviH/mbQFfjfTz4V50KygG9Cy0B0xGn1Q6W8qd5Iw0aZuup3 4EclWLdcuCCpA== From: Sasha Levin To: stable@vger.kernel.org Cc: Runyu Xiao , Takashi Iwai , Sasha Levin Subject: [PATCH 6.12.y] ALSA: mpu401: shut down timer before freeing MPU Date: Tue, 10 Nov 2026 12:01:44 -0500 Message-ID: <20261110170127.2610182-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107051758-failed-6.12-9332af5220d4@kernel.org> References: <20261107051758-failed-6.12-9332af5220d4@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Runyu Xiao [ Upstream commit 9332af5220d42341bb1446a62c545c0518e990ef ] When an MPU401 interface has no usable IRQ, the driver polls raw-MIDI input and output with a timer. During raw-MIDI teardown, the timer callback can already be running when snd_mpu401_uart_remove_timer() clears the last mode bit and calls timer_delete(). That API neither waits for a running callback nor prevents it from rearming the timer, and free_irq() does not synchronize timer callbacks. snd_mpu401_uart_free() can therefore release mpu while the timer callback still uses it. Initialize the timer once when the MPU object is created and only rearm it while a timer mode is active. Shut it down synchronously after freeing the IRQ so an in-flight callback completes before mpu and its resources are released. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Runyu Xiao Link: https://patch.msgid.link/20260927093809.681726-1-runyu.xiao@seu.edu.cn Signed-off-by: Takashi Iwai [ sashal: Adapted scoped_guard() locking to the existing spin_lock_irqsave() and spin_unlock_irqrestore() calls. ] Signed-off-by: Sasha Levin --- sound/drivers/mpu401/mpu401_uart.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sound/drivers/mpu401/mpu401_uart.c b/sound/drivers/mpu401/mpu401_uart.c index 8e3318e177179..86235aefab02d 100644 --- a/sound/drivers/mpu401/mpu401_uart.c +++ b/sound/drivers/mpu401/mpu401_uart.c @@ -162,14 +162,15 @@ static void snd_mpu401_uart_timer(struct timer_list *t) spin_lock_irqsave(&mpu->timer_lock, flags); /*mpu->mode |= MPU401_MODE_TIMER;*/ - mod_timer(&mpu->timer, 1 + jiffies); + if (mpu->timer_invoked) + mod_timer(&mpu->timer, 1 + jiffies); spin_unlock_irqrestore(&mpu->timer_lock, flags); if (mpu->rmidi) _snd_mpu401_uart_interrupt(mpu); } /* - * initialize the timer callback if not programmed yet + * arm the timer if it is not already active */ static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input) { @@ -177,7 +178,6 @@ static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input) spin_lock_irqsave (&mpu->timer_lock, flags); if (mpu->timer_invoked == 0) { - timer_setup(&mpu->timer, snd_mpu401_uart_timer, 0); mod_timer(&mpu->timer, 1 + jiffies); } mpu->timer_invoked |= input ? MPU401_MODE_INPUT_TIMER : @@ -493,6 +493,7 @@ static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi) struct snd_mpu401 *mpu = rmidi->private_data; if (mpu->irq >= 0) free_irq(mpu->irq, (void *) mpu); + timer_shutdown_sync(&mpu->timer); release_and_free_resource(mpu->res); kfree(mpu); } @@ -547,6 +548,7 @@ int snd_mpu401_uart_new(struct snd_card *card, int device, spin_lock_init(&mpu->input_lock); spin_lock_init(&mpu->output_lock); spin_lock_init(&mpu->timer_lock); + timer_setup(&mpu->timer, snd_mpu401_uart_timer, 0); mpu->hardware = hardware; mpu->irq = -1; mpu->rmidi = rmidi; -- 2.53.0