From 09631c84ac395e8da3c4d45722da7c9e7eb1062c Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Mon, 21 Jan 2019 12:09:30 +0100 Subject: [PATCH] rtc: s3c: Rewrite clock handling s3c_rtc_enable/disable_clk() functions were designed to be called multiple times without reference counting, because they were initially only used in alarm setting/clearing functions, which can be called both when alarm is already set or not. Later however, calls to those functions have been added to other places in the driver - like time and /proc reading callbacks, what results in broken alarm if any of such events happens after the alarm has been set. Fix this by simplifying s3c_rtc_enable/disable_clk() functions to rely on proper reference counting in clock core and move alarm enable counter to s3c_rtc_setaie() function. Signed-off-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni [backport of mainline commit 5a5b614ba61cc2a89ad0dffc63d913a1a6ba1f9f] Signed-off-by: Marek Szyprowski Change-Id: Ib72a76ea0567ece0b7b5b706f2ee3b6cca850150 --- drivers/rtc/rtc-s3c.c | 74 +++++++++++++++++++++------------------------------ 1 file changed, 31 insertions(+), 43 deletions(-) diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c index 4120a30..624ca24 100644 --- a/drivers/rtc/rtc-s3c.c +++ b/drivers/rtc/rtc-s3c.c @@ -39,7 +39,7 @@ struct s3c_rtc { void __iomem *base; struct clk *rtc_clk; struct clk *rtc_src_clk; - bool clk_disabled; + bool alarm_enabled; const struct s3c_rtc_data *data; @@ -47,7 +47,7 @@ struct s3c_rtc { int irq_tick; spinlock_t pie_lock; - spinlock_t alarm_clk_lock; + spinlock_t alarm_lock; int ticnt_save; int ticnt_en_save; @@ -70,44 +70,27 @@ struct s3c_rtc_data { static int s3c_rtc_enable_clk(struct s3c_rtc *info) { - unsigned long irq_flags; - int ret = 0; + int ret; - spin_lock_irqsave(&info->alarm_clk_lock, irq_flags); + ret = clk_enable(info->rtc_clk); + if (ret) + return ret; - if (info->clk_disabled) { - ret = clk_enable(info->rtc_clk); - if (ret) - goto out; - - if (info->data->needs_src_clk) { - ret = clk_enable(info->rtc_src_clk); - if (ret) { - clk_disable(info->rtc_clk); - goto out; - } + if (info->data->needs_src_clk) { + ret = clk_enable(info->rtc_src_clk); + if (ret) { + clk_disable(info->rtc_clk); + return ret; } - info->clk_disabled = false; } - -out: - spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags); - - return ret; + return 0; } static void s3c_rtc_disable_clk(struct s3c_rtc *info) { - unsigned long irq_flags; - - spin_lock_irqsave(&info->alarm_clk_lock, irq_flags); - if (!info->clk_disabled) { - if (info->data->needs_src_clk) - clk_disable(info->rtc_src_clk); - clk_disable(info->rtc_clk); - info->clk_disabled = true; - } - spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags); + if (info->data->needs_src_clk) + clk_disable(info->rtc_src_clk); + clk_disable(info->rtc_clk); } /* IRQ Handlers */ @@ -135,6 +118,7 @@ static irqreturn_t s3c_rtc_alarmirq(int irq, void *id) static int s3c_rtc_setaie(struct device *dev, unsigned int enabled) { struct s3c_rtc *info = dev_get_drvdata(dev); + unsigned long flags; unsigned int tmp; int ret; @@ -151,17 +135,19 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled) writeb(tmp, info->base + S3C2410_RTCALM); - s3c_rtc_disable_clk(info); + spin_lock_irqsave(&info->alarm_lock, flags); - if (enabled) { - ret = s3c_rtc_enable_clk(info); - if (ret) - return ret; - } else { + if (info->alarm_enabled && !enabled) s3c_rtc_disable_clk(info); - } + else if (!info->alarm_enabled && enabled) + ret = s3c_rtc_enable_clk(info); - return 0; + info->alarm_enabled = enabled; + spin_unlock_irqrestore(&info->alarm_lock, flags); + + s3c_rtc_disable_clk(info); + + return ret; } /* Set RTC frequency */ @@ -369,10 +355,10 @@ static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) writeb(alrm_en, info->base + S3C2410_RTCALM); - s3c_rtc_disable_clk(info); - s3c_rtc_setaie(dev, alrm->enabled); + s3c_rtc_disable_clk(info); + return 0; } @@ -503,7 +489,7 @@ static int s3c_rtc_probe(struct platform_device *pdev) return -EINVAL; } spin_lock_init(&info->pie_lock); - spin_lock_init(&info->alarm_clk_lock); + spin_lock_init(&info->alarm_lock); platform_set_drvdata(pdev, info); @@ -603,6 +589,8 @@ static int s3c_rtc_probe(struct platform_device *pdev) s3c_rtc_setfreq(info, 1); + s3c_rtc_disable_clk(info); + return 0; err_nortc: -- 2.7.4