diff mbox

[4/5] drivers/rtc/pl030: Replace deprecated rtc_tm_to_time() and rtc_time_to_tm()

Message ID 1429089611-29776-4-git-send-email-xlpang@126.com
State Rejected
Headers show

Commit Message

Xunlei Pang April 15, 2015, 9:20 a.m. UTC 
From: Xunlei Pang <pang.xunlei@linaro.org>

The driver uses deprecated rtc_tm_to_time() and rtc_time_to_tm(),
which will overflow in year 2106 on 32-bit machines.

This patch solves this by:
 - Replacing rtc_tm_to_time() with rtc_tm_to_time64()
 - Replacing rtc_time_to_tm() with rtc_time64_to_tm()

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
---
 drivers/rtc/rtc-pl030.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

Comments

Russell King - ARM Linux April 15, 2015, 9:35 a.m. UTC | #1 
On Wed, Apr 15, 2015 at 05:20:10PM +0800, Xunlei Pang wrote:
> From: Xunlei Pang <pang.xunlei@linaro.org>
> 
> The driver uses deprecated rtc_tm_to_time() and rtc_time_to_tm(),
> which will overflow in year 2106 on 32-bit machines.
> 
> This patch solves this by:
>  - Replacing rtc_tm_to_time() with rtc_tm_to_time64()
>  - Replacing rtc_time_to_tm() with rtc_time64_to_tm()
> 
> Cc: Russell King <rmk+kernel@arm.linux.org.uk>
> Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>

NAK.

How does this fix anything?  The RTC contains 32-bit registers.  Even
if you convert the struct tm to a 64-bit time, you can only write the
lowest 32-bits to the hardware.  You can onyl read the lowest 32-bits
from the hardware too.

This patch solves /nothing/.  In fact, it hides the fact that this RTC
is unable to represent dates after 2106.
diff mbox

Patch

diff --git a/drivers/rtc/rtc-pl030.c b/drivers/rtc/rtc-pl030.c
index f85a1a9..d874b6e 100644
--- a/drivers/rtc/rtc-pl030.c
+++ b/drivers/rtc/rtc-pl030.c
@@ -39,32 +39,34 @@  static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct pl030_rtc *rtc = dev_get_drvdata(dev);
 
-	rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
+	rtc_time64_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
 	return 0;
 }
 
 static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct pl030_rtc *rtc = dev_get_drvdata(dev);
-	unsigned long time;
+	time64_t time;
 	int ret;
 
 	/*
 	 * At the moment, we can only deal with non-wildcarded alarm times.
 	 */
 	ret = rtc_valid_tm(&alrm->time);
-	if (ret == 0)
-		ret = rtc_tm_to_time(&alrm->time, &time);
-	if (ret == 0)
-		writel(time, rtc->base + RTC_MR);
-	return ret;
+	if (ret)
+		return ret;
+
+	time = rtc_tm_to_time64(&alrm->time);
+	writel(time, rtc->base + RTC_MR);
+
+	return 0;
 }
 
 static int pl030_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct pl030_rtc *rtc = dev_get_drvdata(dev);
 
-	rtc_time_to_tm(readl(rtc->base + RTC_DR), tm);
+	rtc_time64_to_tm(readl(rtc->base + RTC_DR), tm);
 
 	return 0;
 }
@@ -80,14 +82,12 @@  static int pl030_read_time(struct device *dev, struct rtc_time *tm)
 static int pl030_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct pl030_rtc *rtc = dev_get_drvdata(dev);
-	unsigned long time;
-	int ret;
+	time64_t time;
 
-	ret = rtc_tm_to_time(tm, &time);
-	if (ret == 0)
-		writel(time + 1, rtc->base + RTC_LR);
+	time = rtc_tm_to_time64(tm);
+	writel(time + 1, rtc->base + RTC_LR);
 
-	return ret;
+	return 0;
 }
 
 static const struct rtc_class_ops pl030_ops = {