Message ID | 1359551760-28862-1-git-send-email-s.trumtrar@pengutronix.de |
---|---|
State | New |
Headers | show |
On Wed, Jan 30, 2013 at 02:16:00PM +0100, Steffen Trumtrar wrote: > 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 <s.trumtrar@pengutronix.de> > Cc: stable@vger.kernel.org # v3.5+ Applied, thanks Sascha > --- > 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 5d34f67..0e6dde6 100644 > --- a/arch/arm/mach-imx/clk-imx25.c > +++ b/arch/arm/mach-imx/clk-imx25.c > @@ -177,6 +177,9 @@ static int __init __mx25_clocks_init(unsigned long osc_rate) > pr_err("i.MX25 clk %d: register failed with %ld\n", > i, PTR_ERR(clk[i])); > > + /* 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"); > > -- > 1.7.10.4 > >
diff --git a/arch/arm/mach-imx/clk-imx25.c b/arch/arm/mach-imx/clk-imx25.c index 5d34f67..0e6dde6 100644 --- a/arch/arm/mach-imx/clk-imx25.c +++ b/arch/arm/mach-imx/clk-imx25.c @@ -177,6 +177,9 @@ static int __init __mx25_clocks_init(unsigned long osc_rate) pr_err("i.MX25 clk %d: register failed with %ld\n", i, PTR_ERR(clk[i])); + /* 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");
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 <s.trumtrar@pengutronix.de> Cc: stable@vger.kernel.org # v3.5+ --- arch/arm/mach-imx/clk-imx25.c | 3 +++ 1 file changed, 3 insertions(+)