From nobody Sat Oct 4 04:56:51 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6FCCB31DD8D; Wed, 20 Aug 2025 15:48:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755704924; cv=none; b=iGIMV7vsGwnItWFfNX+2UPFmE64Ttf8Sdee8DHR9MU7xrQ8nDDxoX49QQ7IP+m915/jkM6lfoK60SQ3UxTxAEWj6wZhy5CD2ljLcRKuLzxkI4g98jEVDJ1AHUA1bfgxQWdO85qYLg0USnr9wheqisJCtoKjWPvD38RbedhuxPQM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755704924; c=relaxed/simple; bh=3jk8lXKf8bNegg8oz1RN0LjzQDm8KFDzfVDm5LG70DM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N2OKATwu/v8KlIfb7UdQeM7zT0/ap7Gp5WJsYxNKiYw6b43gp6ZSRdWlNTSZAeGalpAPh1ZdpDQmXikFBGgFqtfxPuFN85KLzcjSu7yRD9US97f7JL9X1e2bRYXlqvYzt1GaA4EtULEc81s9NAsV+TopwvXTq0CPnUsg7SToMtE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=u45PGUAp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="u45PGUAp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 491F9C113CF; Wed, 20 Aug 2025 15:48:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755704923; bh=3jk8lXKf8bNegg8oz1RN0LjzQDm8KFDzfVDm5LG70DM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u45PGUApdLxBEi0dRsM6LsgkDNwdc0yvQ7tuxroApvKBCckDQ87GEJLyJASVwi+wL wLC08L/VbJ+lYVnQP9yx7docx/UiX+IpQzz5/9y1TsVL13aGgJnoBmJNUm8R5RRHlc EjWXHfrRdDANZuGpTbhvQtiW0PbawWVrXQHzwhhRup4OJNeeZFc33H7AXveNctWjjc MM2FXmruM9mAHEbbAUd2s/FonBCmLazFKspkBAG42Ph7bYmHedzTcRoO8Jm2XbdFlr bIuTW1r6WP6VRv5F5KzzxVxHMydfrtSgiaDTaf5OKHvQlK7MhuBMCrl4LDvLdxa6aH dDYxjzOELTaOg== From: Jisheng Zhang To: Jarkko Nikula , Andy Shevchenko , Mika Westerberg , Jan Dabros , Andi Shyti Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org Subject: [PATCH 1/2] i2c: designware: Avoid taking clk_prepare mutex in PM callbacks Date: Wed, 20 Aug 2025 23:31:24 +0800 Message-ID: <20250820153125.22002-2-jszhang@kernel.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250820153125.22002-1-jszhang@kernel.org> References: <20250820153125.22002-1-jszhang@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This is unsafe, as the runtime PM callbacks are called from the PM workqueue, so this may deadlock when handling an i2c attached clock, which may already hold the clk_prepare mutex from another context. Fixes: 1fc2fe204cb9 ("i2c: designware: Add runtime PM hooks") Signed-off-by: Jisheng Zhang --- drivers/i2c/busses/i2c-designware-common.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busse= s/i2c-designware-common.c index 5b1e8f74c4ac..b4e38bc0f876 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -776,7 +776,8 @@ static int i2c_dw_runtime_suspend(struct device *device) return 0; =20 i2c_dw_disable(dev); - i2c_dw_prepare_clk(dev, false); + clk_disable(dev->clk); + clk_disable(dev->pclk); =20 return 0; } @@ -794,8 +795,10 @@ static int i2c_dw_runtime_resume(struct device *device) { struct dw_i2c_dev *dev =3D dev_get_drvdata(device); =20 - if (!dev->shared_with_punit) - i2c_dw_prepare_clk(dev, true); + if (!dev->shared_with_punit) { + clk_enable(dev->pclk); + clk_enable(dev->clk); + } =20 dev->init(dev); =20 --=20 2.50.1