From patchwork Wed Mar 14 03:24:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bryan O'Donoghue X-Patchwork-Id: 885602 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-rtc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=nexus-software.ie Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=nexus-software-ie.20150623.gappssmtp.com header.i=@nexus-software-ie.20150623.gappssmtp.com header.b="CxHa8byz"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 401HCj2LzJz9sV5 for ; Wed, 14 Mar 2018 14:25:05 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933238AbeCNDZE (ORCPT ); Tue, 13 Mar 2018 23:25:04 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:34503 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932937AbeCNDZD (ORCPT ); Tue, 13 Mar 2018 23:25:03 -0400 Received: by mail-wm0-f67.google.com with SMTP id a20so16486295wmd.1 for ; Tue, 13 Mar 2018 20:25:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nexus-software-ie.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=+zP1DjaL91xvpKSN9tdnhidy7q7iN8r2YpLFEXFwPwA=; b=CxHa8byzSxE4qa5GIERSOTYLxQPXFPPPWejN0Kfyj7YE8TCZHSTqBdnHEukXkakWdR BJw+n9F7uyaNWDnmGO+z0fgXQGkic5uYs+EUJPtnN/gEVRXGOumiuePUQ4HNA0UUdqTv N6UQ1sz6xgAZhp1IhBk0Rq6NUmnHx44ZRPBLOknQvyzlz75Yvy+z4iSRWZFXYZ9ixGJ7 ljKiCe5VaOVIzDvkUlQ3Icjq5bKAW6+e09OohC4YHHf+nt56dF2nnIgdfZZWwlLfzO7r p1GxQwNMJPlF2DCdg4S06IfK2jGuRGRrcxxVoR8yABvE55rZ7zPgKchaQdsMzib2K+SS DGTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=+zP1DjaL91xvpKSN9tdnhidy7q7iN8r2YpLFEXFwPwA=; b=Xja7oX1hk8l2livBbIilnC49Q8pOi4iD7hebvNjtvBvExjhure8mCAkhBrEC/g+Ke0 GpDTYW2xv4t8kaCZThBMe5E9bdlsjQ15YNKSBvlnYskeR4pctDdlemACpwbq7U0OmDad BSo6UrXNdBhDElfST6HhgzE7ueCexn3zJDw+8IBzKn7ZyBbcVKGDgdXcLe2lRuTQvw81 VBbputMTTIxxV5DFd6e+78lqHI0yfF9g0MgNEMEisWKFbOxRARgF4dv0ysArUBb2nef6 eVfX9NoMOD/hzjfPSgz6C9aenMbqzB6DlhZ6HKjwfMGbIhPnmZPowtwkMCzicXiQmwf0 ypCg== X-Gm-Message-State: AElRT7H6bv9ZkguiV21bkYv3qz5oPlMKRmOTSb2zS6u0w2nzaT+nHimN c8zZ5PrD9o5kZOSk1H0wv8RtXQ== X-Google-Smtp-Source: AG47ELtpTpP658r8tQrdkqq/16BMeCIEQT3JqHVhL54K55kxUs8F0deDUIvOv+90vd+NVlPg+YemfA== X-Received: by 10.80.240.213 with SMTP id a21mr3048068edm.77.1520997901833; Tue, 13 Mar 2018 20:25:01 -0700 (PDT) Received: from localhost.localdomain ([109.255.42.2]) by smtp.gmail.com with ESMTPSA id g17sm1206129edh.55.2018.03.13.20.25.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 13 Mar 2018 20:25:01 -0700 (PDT) From: Bryan O'Donoghue To: alexandre.belloni@free-electrons.com Cc: Bryan O'Donoghue , a.zummo@towertech.it, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, "# v3 . 16+" Subject: [PATCH] rtc: snvs: Fix usage of snvs_rtc_enable Date: Wed, 14 Mar 2018 03:24:59 +0000 Message-Id: <1520997899-18445-1-git-send-email-pure.logic@nexus-software.ie> X-Mailer: git-send-email 2.7.4 Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org commit 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver") introduces the SNVS RTC driver with a function snvs_rtc_enable(). snvs_rtc_enable() can return an error on the enable path however this driver does not currently trap that failure on the probe() path and consequently if enabling the RTC fails we encounter a later error spinning forever in rtc_write_sync_lp(). [ 36.093481] [] (__irq_svc) from [] (_raw_spin_unlock_irqrestore+0x34/0x44) [ 36.102122] [] (_raw_spin_unlock_irqrestore) from [] (regmap_read+0x4c/0x5c) [ 36.110938] [] (regmap_read) from [] (rtc_write_sync_lp+0x6c/0x98) [ 36.118881] [] (rtc_write_sync_lp) from [] (snvs_rtc_alarm_irq_enable+0x40/0x4c) [ 36.128041] [] (snvs_rtc_alarm_irq_enable) from [] (rtc_timer_do_work+0xd8/0x1a8) [ 36.137291] [] (rtc_timer_do_work) from [] (process_one_work+0x28c/0x76c) [ 36.145840] [] (process_one_work) from [] (worker_thread+0x34/0x58c) [ 36.153961] [] (worker_thread) from [] (kthread+0x138/0x150) [ 36.161388] [] (kthread) from [] (ret_from_fork+0x14/0x20) [ 36.168635] rcu_sched kthread starved for 2602 jiffies! g496 c495 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 [ 36.178564] rcu_sched R running task 0 8 2 0x00000000 [ 36.185664] [] (__schedule) from [] (schedule+0x3c/0xa0) [ 36.192739] [] (schedule) from [] (schedule_timeout+0x78/0x4e0) [ 36.200422] [] (schedule_timeout) from [] (rcu_gp_kthread+0x648/0x1864) [ 36.208800] [] (rcu_gp_kthread) from [] (kthread+0x138/0x150) [ 36.216309] [] (kthread) from [] (ret_from_fork+0x14/0x20) This patch fixes by parsing the result of rtc_write_sync_lp() and propagating both in the probe and elsewhere. If the RTC doesn't start we don't proceed loading the driver and don't get into this loop mess later on. Fixes: 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver") Signed-off-by: Bryan O'Donoghue Cc: a.zummo@towertech.it Cc: alexandre.belloni@free-electrons.com Cc: linux-rtc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: # v3.16+ --- drivers/rtc/rtc-snvs.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c index d8ef9e0..9af591d 100644 --- a/drivers/rtc/rtc-snvs.c +++ b/drivers/rtc/rtc-snvs.c @@ -132,20 +132,23 @@ static int snvs_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct snvs_rtc_data *data = dev_get_drvdata(dev); unsigned long time; + int ret; rtc_tm_to_time(tm, &time); /* Disable RTC first */ - snvs_rtc_enable(data, false); + ret = snvs_rtc_enable(data, false); + if (ret) + return ret; /* Write 32-bit time to 47-bit timer, leaving 15 LSBs blank */ regmap_write(data->regmap, data->offset + SNVS_LPSRTCLR, time << CNTR_TO_SECS_SH); regmap_write(data->regmap, data->offset + SNVS_LPSRTCMR, time >> (32 - CNTR_TO_SECS_SH)); /* Enable RTC again */ - snvs_rtc_enable(data, true); + ret = snvs_rtc_enable(data, true); - return 0; + return ret; } static int snvs_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) @@ -288,7 +291,11 @@ static int snvs_rtc_probe(struct platform_device *pdev) regmap_write(data->regmap, data->offset + SNVS_LPSR, 0xffffffff); /* Enable RTC */ - snvs_rtc_enable(data, true); + ret = snvs_rtc_enable(data, true); + if (ret) { + dev_err(&pdev->dev, "failed to enable rtc %d\n", ret); + goto error_rtc_device_register; + } device_init_wakeup(&pdev->dev, true);