Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 182/186] rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq() | Date | Thu, 18 Aug 2016 15:59:59 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Alim Akhtar <alim.akhtar@samsung.com>
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") 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/rtc/rtc-s3c.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/rtc/rtc-s3c.c +++ b/drivers/rtc/rtc-s3c.c @@ -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; }
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