From mboxrd@z Thu Jan 1 00:00:00 1970 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: 8bit 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/busses/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; i2c_dw_disable(dev); - i2c_dw_prepare_clk(dev, false); + clk_disable(dev->clk); + clk_disable(dev->pclk); return 0; } @@ -794,8 +795,10 @@ static int i2c_dw_runtime_resume(struct device *device) { struct dw_i2c_dev *dev = dev_get_drvdata(device); - if (!dev->shared_with_punit) - i2c_dw_prepare_clk(dev, true); + if (!dev->shared_with_punit) { + clk_enable(dev->pclk); + clk_enable(dev->clk); + } dev->init(dev); -- 2.50.1