From 4b526ca5f627188425184a22ed46c91baa602d43 Mon Sep 17 00:00:00 2001 From: Steffen Trumtrar Date: Wed, 30 Jan 2013 14:16:00 +0100 Subject: [PATCH] ARM: i.MX25: clk: parent per5_clk to AHB clock The mxc-timer on the imx25 needs to be derived from the AHB clock. If a bootloader reparents this clock to the ipg_clk_highfreq, which according to the datasheet is a valid operation, the system can/will produce lockups/ freezes after some time [1]. This can be forced with code like while(1) syscall(SYS_clock_gettime, CLOCK_REALTIME, &tp); This was already fixed with the commit "i.MX25 GPT clock fix: ensure correct the clock source" [2], for 3.1-rc2, but was lost, when i.MX was converted to the common clock framework ("ARM i.MX25: implement clocks using common clock framework") [3] [1]: http://lists.arm.linux.org.uk/lurker/message/20130129.161230.229bda17.en.html [2]: 2012d9ca2a1381ae3e733330a7f0d1d2f1988bba [3]: 6bbaec5676e4f475b0d78743cbd4c70a8804ce14 Signed-off-by: Steffen Trumtrar Cc: stable@vger.kernel.org # v3.5+ Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/clk-imx25.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mach-imx/clk-imx25.c b/arch/arm/mach-imx/clk-imx25.c index 2c570cdaae7b..69858c78f40d 100644 --- a/arch/arm/mach-imx/clk-imx25.c +++ b/arch/arm/mach-imx/clk-imx25.c @@ -224,6 +224,9 @@ static int __init __mx25_clocks_init(unsigned long osc_rate) clk_prepare_enable(clk[emi_ahb]); + /* Clock source for gpt must be derived from AHB */ + clk_set_parent(clk[per5_sel], clk[ahb]); + clk_register_clkdev(clk[ipg], "ipg", "imx-gpt.0"); clk_register_clkdev(clk[gpt_ipg_per], "per", "imx-gpt.0"); -- 2.11.4.GIT