-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/16/2011 08:57 AM, Linus Walleij wrote: > On Fri, Dec 16, 2011 at 6:56 AM, Daniel Lezcano > <daniel.lezc...@linaro.org> wrote: >> [Me] >>> what happens if you just reactivate CPUfreq then use menuconfig >>> to go into drivers/ directly you will see the >>> "Clocksource PRCMU Timer" (sorry the clksrc subsystem does not >>> have its own submenu...), deselect that so as to use the >>> more monotone MTU clock source (it lives up in >>> arch/arm/plat-nomadik/timer.c by the way), what happens? >> >> I am still seeing the problem ... :/ > > Hm, let's see what we know: > > - It's not due to the clocksources - we tried two of them > (both actually known to be good and stable) since the same > timers are used for sched_clock that is probably not the > cause either. > - It's related to CPUfreq > - Localtimer smp_twd CPUfreq patches does not help on > their own > > But my commit ef7a474cef00594ccef432ce0840464e51ea4ac0 > adding the smp_twd clock may be giving the wrong frequency > to the localtimer. This is on the eternal TODO to fix up > the clock implementation for ux500. > > Rabin fixed this in the non-mainline kernel: > http://git.linaro.org/gitweb?p=bsp/st-ericsson/linux-3.0-ux500.git;a=commitdiff;h=0270d85bed4ff4f24b3aa79fe878c4ad6c5c4d5b > > As you can see it hacks around in a quite different > version of the CPUfreq driver (yes that needs to be fixed > up too). > > I should have thought about that immediately :-/ Too much in > my head. > > Can you try something like the below (together with the three > smp_twd patches) to see if it solves the problem? It's an ugly > fix though, the clock implementation and CPUfreq driver both > needs to be fixed for real. > > diff --git a/arch/arm/mach-ux500/clock.c b/arch/arm/mach-ux500/clock.c > index e832664..60378b3 100644 > --- a/arch/arm/mach-ux500/clock.c > +++ b/arch/arm/mach-ux500/clock.c > @@ -743,7 +743,8 @@ err_out: > late_initcall(clk_debugfs_init); > #endif /* defined(CONFIG_DEBUG_FS) */ > > -unsigned long clk_smp_twd_rate = 400000000; > +/* Half the max CPU frequency on most systems (UGLY ASSUMPTION!) */ > +unsigned long clk_smp_twd_rate = 500000000; > > unsigned long clk_smp_twd_get_rate(struct clk *clk) > { > @@ -769,7 +770,7 @@ static int clk_twd_cpufreq_transition(struct > notifier_block *nb, > > if (state == CPUFREQ_PRECHANGE) { > /* Save frequency in simple Hz */ > - clk_smp_twd_rate = f->new * 1000; > + clk_smp_twd_rate = (f->new * 1000) / 2; > }
Hi Linus, That fixes the problem. Are you planning to send a fix to lakml ? Thanks -- Daniel - -- <http://www.linaro.org/> Linaro.org ? Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJO65n2AAoJEAKBbMCpUGYAe1EH/1dzBLpLhjoZsz98Sbm4X3my PspxxHYwx00XSReuQya/ssj1Jmhtdlu+BO0sgTGZqqCEeyDs7H59dpr66Ip3n6WQ z0heAZgqekqBLN5oBFvZb5+Z223eVv7zl0g+ksCEztWJiY7+KY46f0dpr/d435DL 6fyqg5HY24TxsVgIn6RBh3rv+zPwgN19LgwFYTRZ5toWhku88iTQXOyVpSNsB65u VagHxvy80xKEkj/UdNLtJRVaTRDKCVyycRPYw9amgRakSZAStQl5cZjXbYYdim7R RwpYXzPUkU24RptEd8R/zi6WYCt4VpE6Zk0RwaFwwwT/iqq+Z0oHlaiUoyv0GIM= =XS1C -----END PGP SIGNATURE----- _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
