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Patch "rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()" has been added to the 4.7-stable tree

PATCH [email protected] 1 participant 1 message Aug 18, 2016

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This is a note to let you know that I've just added the patch titled

rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()

to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:

     rtc-s3c-add-s3c_rtc_-enable-disable-_clk-in-s3c_rtc_setfreq.patch

and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 70c96dfac0e231424e17743bd52f6cd2ff1f2439 Mon Sep 17 00:00:00 2001

From: Alim Akhtar <[email protected]>
Date: Tue, 5 Jul 2016 15:28:53 +0530
Subject: rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()

From: Alim Akhtar <[email protected]>

commit 70c96dfac0e231424e17743bd52f6cd2ff1f2439 upstream.

As per code flow s3c_rtc_setfreq() will get called with rtc clock disabled and in set_freq we perform h/w registers read/write, which results in a kernel crash on exynos7 platform while probing rtc driver.
Below is code flow:
s3c_rtc_probe()
clk_prepare_enable(info->rtc_clk) // rtc clock enabled s3c_rtc_gettime() // will enable clk if not done, and disable it upon exit s3c_rtc_setfreq() //then this will be called with clk disabled

This patch take cares of such issue by adding s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq().

Fixes 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock control")
---
 drivers/rtc/rtc-s3c.c |    2 ++
 1 file changed, 2 insertions(+)
drivers/rtc/rtc-s3c.c +2 -0
@@ -149,12 +149,14 @@ static int s3c_rtc_setfreq(struct s3c_rt
 	if (!is_power_of_2(freq))
 		return -EINVAL;
 
+	s3c_rtc_enable_clk(info);
 	spin_lock_irq(&info->pie_lock);
 
 	if (info->data->set_freq)
 		info->data->set_freq(info, freq);
 
 	spin_unlock_irq(&info->pie_lock);
+	s3c_rtc_disable_clk(info);
 
 	return 0;
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/regulator-s2mps11-fix-the-voltage-linear-range-for-s2mps15.patch queue-4.7/rtc-s3c-add-s3c_rtc_-enable-disable-_clk-in-s3c_rtc_setfreq.patch