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 B3EDD1C29 for ; Wed, 23 Nov 2022 09:30:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 307C1C433D7; Wed, 23 Nov 2022 09:30:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669195859; bh=7F/t3BCaqQ52NSh+yPgrBxY/e0O2jmGG/dw4tg+V2Hw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yRbeJ5jCgYSur9ULSoQN+WHM0sPjWWx4ERnFTkn7v3qMJg+PdQx+hRAkGM0CySx6y ICSMLpraiDfCmGAssWQQXDcpUz3zvvKTuhx/m3Ug0HtuYfzw6pecWo2slqUWIk6OSN YafXNJm4M2mHH3DWH3xvahTwwkz9PAclPTMa+lOs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Martin Kaiser , Shawn Guo , Sasha Levin Subject: [PATCH 5.15 052/181] serial: imx: Add missing .thaw_noirq hook Date: Wed, 23 Nov 2022 09:50:15 +0100 Message-Id: <20221123084604.621404983@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084602.707860461@linuxfoundation.org> References: <20221123084602.707860461@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Shawn Guo [ Upstream commit 4561d8008a467cb05ac632a215391d6b787f40aa ] The following warning is seen with non-console UART instance when system hibernates. [ 37.371969] ------------[ cut here ]------------ [ 37.376599] uart3_root_clk already disabled [ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0 ... [ 37.506986] Call trace: [ 37.509432] clk_core_disable+0xa4/0xb0 [ 37.513270] clk_disable+0x34/0x50 [ 37.516672] imx_uart_thaw+0x38/0x5c [ 37.520250] platform_pm_thaw+0x30/0x6c [ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4 [ 37.528972] device_resume+0x7c/0x160 [ 37.532633] dpm_resume+0xe8/0x230 [ 37.536036] hibernation_snapshot+0x288/0x430 [ 37.540397] hibernate+0x10c/0x2e0 [ 37.543798] state_store+0xc4/0xd0 [ 37.547203] kobj_attr_store+0x1c/0x30 [ 37.550953] sysfs_kf_write+0x48/0x60 [ 37.554619] kernfs_fop_write_iter+0x118/0x1ac [ 37.559063] new_sync_write+0xe8/0x184 [ 37.562812] vfs_write+0x230/0x290 [ 37.566214] ksys_write+0x68/0xf4 [ 37.569529] __arm64_sys_write+0x20/0x2c [ 37.573452] invoke_syscall.constprop.0+0x50/0xf0 [ 37.578156] do_el0_svc+0x11c/0x150 [ 37.581648] el0_svc+0x30/0x140 [ 37.584792] el0t_64_sync_handler+0xe8/0xf0 [ 37.588976] el0t_64_sync+0x1a0/0x1a4 [ 37.592639] ---[ end trace 56e22eec54676d75 ]--- On hibernating, pm core calls into related hooks in sequence like: .freeze .freeze_noirq .thaw_noirq .thaw With .thaw_noirq hook being absent, the clock will be disabled in a unbalanced call which results the warning above. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_thaw clk_disable_unprepare() Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have the call sequence corrected as below and thus fix the warning. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_resume_noirq() clk_enable() imx_uart_thaw clk_disable_unprepare() Fixes: 09df0b3464e5 ("serial: imx: fix endless loop during suspend") Reviewed-by: Martin Kaiser Signed-off-by: Shawn Guo Link: https://lore.kernel.org/r/20221012121353.2346280-1-shawn.guo@linaro.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/imx.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index c6a93d6a9464..711edb835c27 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2563,6 +2563,7 @@ static const struct dev_pm_ops imx_uart_pm_ops = { .suspend_noirq = imx_uart_suspend_noirq, .resume_noirq = imx_uart_resume_noirq, .freeze_noirq = imx_uart_suspend_noirq, + .thaw_noirq = imx_uart_resume_noirq, .restore_noirq = imx_uart_resume_noirq, .suspend = imx_uart_suspend, .resume = imx_uart_resume, -- 2.35.1