From patchwork Mon Sep 30 19:27:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 13816898 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 21A1FCDD1A9 for ; Mon, 30 Sep 2024 19:29:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=OREwX1JcqK3oMMSoTvHvNaOWPllgrNDfzP8nZJ/yKEw=; b=zrBfnZrXgh+pk3GuMi9sdUjJPu Uo70hT1o+alHjCtNehRogxptw6ODMSSdIwRsHJutAgxkcc5v2Q3lj8yyQm8OFtG15Q07ocVZd+wXk tgaX6CLd9xhXGCb69JZHutsdAN54S8yKPEVhoGhUHPx+xS/mt/V+MgDf9b1RMvqNu4LKlXL3W7X5K ASisyuokgedxFmQsYoG6xiyXZeshgDz74gEKPtPVFJlnOP1hEYImMV264Zqsrzmc0EXRyJntuyHa9 jSHNho0fjfeYy/83tbUH36yg7n/fl/0H8Hd91wpV7HT1t3sbPXS65WGvOIQPoz7xnfZ5AUWR2UkXn j708ugNQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1svM5c-00000000dVX-1Jgq; Mon, 30 Sep 2024 19:29:48 +0000 Received: from phobos.denx.de ([85.214.62.61]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1svM4O-00000000dJx-06r3 for linux-arm-kernel@lists.infradead.org; Mon, 30 Sep 2024 19:28:34 +0000 Received: from tr.lan (ip-86-49-120-218.bb.vodafone.cz [86.49.120.218]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 6144A88F6F; Mon, 30 Sep 2024 21:28:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1727724510; bh=OREwX1JcqK3oMMSoTvHvNaOWPllgrNDfzP8nZJ/yKEw=; h=From:To:Cc:Subject:Date:From; b=cq+9CnS9d+E3rGsryG4+eZnuluwTcS9FWDxkyVy7dCJ+3Ca+QxTlmqv010KC0qlht 1VpCmA3OjzuoQtM5U03ronMScYDEviuGM3osMEu4iDe2uyRJv9NLDS969uPLI8lm+0 cyP0Vawvxm4cYEA9VRnMSiAU/EOTvfS8Xot3d2qnYOx1UgM5RE9yyk+w8863ejSRpK JzQkk11k3zdl0Sq1s8ctwG14BGOvqdLUyE6f9xiJCYI3zkr5QaaCdrzdnSVB8np46T WlWunMsO8RudfS85o2LxkhsPYp0tl5XCJJ1iNIFM+TcyZsRLV2IfS8H4+Mcxnz8Kgo DXg8D4Cn14glg== From: Marek Vasut To: linux-i2c@vger.kernel.org Cc: Marek Vasut , Alain Volmat , Alexandre Torgue , Andi Shyti , Christoph Niedermaier , Maxime Coquelin , Pierre-Yves MORDRET , kernel@dh-electronics.com, linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com Subject: [PATCH v2] i2c: stm32f7: Do not prepare/unprepare clock during runtime suspend/resume Date: Mon, 30 Sep 2024 21:27:41 +0200 Message-ID: <20240930192820.59719-1-marex@denx.de> X-Mailer: git-send-email 2.45.2 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240930_122832_387879_F70C7E33 X-CRM114-Status: GOOD ( 13.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org In case there is any sort of clock controller attached to this I2C bus controller, for example Versaclock or even an AIC32x4 I2C codec, then an I2C transfer triggered from the clock controller clk_ops .prepare callback may trigger a deadlock on drivers/clk/clk.c prepare_lock mutex. This is because the clock controller first grabs the prepare_lock mutex and then performs the prepare operation, including its I2C access. The I2C access resumes this I2C bus controller via .runtime_resume callback, which calls clk_prepare_enable(), which attempts to grab the prepare_lock mutex again and deadlocks. Since the clock are already prepared since probe() and unprepared in remove(), use simple clk_enable()/clk_disable() calls to enable and disable the clock on runtime suspend and resume, to avoid hitting the prepare_lock mutex. Acked-by: Alain Volmat Signed-off-by: Marek Vasut --- Cc: Alain Volmat Cc: Alexandre Torgue Cc: Andi Shyti Cc: Christoph Niedermaier Cc: Maxime Coquelin Cc: Pierre-Yves MORDRET Cc: kernel@dh-electronics.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-i2c@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com --- V2: - Update the error message - Add AB from Alain --- drivers/i2c/busses/i2c-stm32f7.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index cfee2d9c09de3..0174ead99de6c 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -2395,7 +2395,7 @@ static int __maybe_unused stm32f7_i2c_runtime_suspend(struct device *dev) struct stm32f7_i2c_dev *i2c_dev = dev_get_drvdata(dev); if (!stm32f7_i2c_is_slave_registered(i2c_dev)) - clk_disable_unprepare(i2c_dev->clk); + clk_disable(i2c_dev->clk); return 0; } @@ -2406,9 +2406,9 @@ static int __maybe_unused stm32f7_i2c_runtime_resume(struct device *dev) int ret; if (!stm32f7_i2c_is_slave_registered(i2c_dev)) { - ret = clk_prepare_enable(i2c_dev->clk); + ret = clk_enable(i2c_dev->clk); if (ret) { - dev_err(dev, "failed to prepare_enable clock\n"); + dev_err(dev, "failed to enable clock\n"); return ret; } }