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authorAlim Akhtar <alim.akhtar@samsung.com>2016-07-05 11:58:53 +0200
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2016-07-19 17:48:06 +0200
commit70c96dfac0e231424e17743bd52f6cd2ff1f2439 (patch)
tree2dbdc99319b4df01179d28bedbc74ec6e70079ec
parentrtc: s3c: Remove unnecessary call to disable already disabled clock (diff)
downloadlinux-70c96dfac0e231424e17743bd52f6cd2ff1f2439.tar.xz
linux-70c96dfac0e231424e17743bd52f6cd2ff1f2439.zip
rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()
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") Cc: <stable@vger.kernel.org> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Pankaj Dubey <pankaj.dubey@samsung.com> Tested-by: Pankaj Dubey <pankaj.dubey@samsung.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
-rw-r--r--drivers/rtc/rtc-s3c.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index 945d84fb1aa6..d44fb34df8fe 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -149,12 +149,14 @@ static int s3c_rtc_setfreq(struct s3c_rtc *info, int freq)
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;
}