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 88E405CD04; Tue, 26 Dec 2023 00:25:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="o6fu21Ed" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D477C433C9; Tue, 26 Dec 2023 00:25:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1703550349; bh=wEme5zOXjNS4jm4i7jwulhr8cvuV5k7DomlCN/6/p40=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o6fu21Ed6WHxPVKs1TCS+3nY2bRYLthl93sXCfvfP6cKEEad2WpzuQjHGsaYuxyRb nGSCMau1t4363ICT1L6Ded0fCkT/LidlefRai4Ldfxbhqf/cT++vNEygOOsHCSOxIr TOZLucKcU486uLNKTCu2T+RRNKHZrfXqtncW2m1cxoXurvTL+sGHYfrdVVzjT8crph qhXIKAtIYBEe+iZJxXV58NmoL2ndW5yt4WvrhxpZAQAxs+1QMk14HKZ/CEvtJHkDIR 8OO6Ojy6qilwiJGS0M764RrqBTWNJEFZ02uo3rBddd48wfmyxieFDHl1TICDXVrEY3 CXDPxkCsS1ftQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jensen Huang , Heiko Stuebner , Andi Shyti , Wolfram Sang , Sasha Levin , linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-i2c@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 8/9] i2c: rk3x: fix potential spinlock recursion on poll Date: Mon, 25 Dec 2023 19:24:52 -0500 Message-ID: <20231226002526.6605-8-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231226002526.6605-1-sashal@kernel.org> References: <20231226002526.6605-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.205 Content-Transfer-Encoding: 8bit From: Jensen Huang [ Upstream commit 19cde9c92b8d3b7ee555d0da3bcb0232d3a784f4 ] Possible deadlock scenario (on reboot): rk3x_i2c_xfer_common(polling) -> rk3x_i2c_wait_xfer_poll() -> rk3x_i2c_irq(0, i2c); --> spin_lock(&i2c->lock); ... -> rk3x_i2c_irq(0, i2c); --> spin_lock(&i2c->lock); (deadlock here) Store the IRQ number and disable/enable it around the polling transfer. This patch has been tested on NanoPC-T4. Signed-off-by: Jensen Huang Reviewed-by: Heiko Stuebner Reviewed-by: Andi Shyti Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-rk3x.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index 13c14eb175e94..6abcf975a2db9 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -178,6 +178,7 @@ struct rk3x_i2c_soc_data { * @clk: function clk for rk3399 or function & Bus clks for others * @pclk: Bus clk for rk3399 * @clk_rate_nb: i2c clk rate change notify + * @irq: irq number * @t: I2C known timing information * @lock: spinlock for the i2c bus * @wait: the waitqueue to wait for i2c transfer @@ -200,6 +201,7 @@ struct rk3x_i2c { struct clk *clk; struct clk *pclk; struct notifier_block clk_rate_nb; + int irq; /* Settings */ struct i2c_timings t; @@ -1087,13 +1089,18 @@ static int rk3x_i2c_xfer_common(struct i2c_adapter *adap, spin_unlock_irqrestore(&i2c->lock, flags); - rk3x_i2c_start(i2c); - if (!polling) { + rk3x_i2c_start(i2c); + timeout = wait_event_timeout(i2c->wait, !i2c->busy, msecs_to_jiffies(WAIT_TIMEOUT)); } else { + disable_irq(i2c->irq); + rk3x_i2c_start(i2c); + timeout = rk3x_i2c_wait_xfer_poll(i2c); + + enable_irq(i2c->irq); } spin_lock_irqsave(&i2c->lock, flags); @@ -1301,6 +1308,8 @@ static int rk3x_i2c_probe(struct platform_device *pdev) return ret; } + i2c->irq = irq; + platform_set_drvdata(pdev, i2c); if (i2c->soc_data->calc_timings == rk3x_i2c_v0_calc_timings) { -- 2.43.0