Re: [PATCH 2a/5] Remove unsafe clock values from omap1_defconfig

From: Janusz Krzysztofik
Date: Thu Dec 01 2011 - 13:39:36 EST


On Thursday 01 of December 2011 at 18:17:58, Tony Lindgren wrote:
> * Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx> [111201 01:20]:
[snip]
> > Perhaps
> > we should rather think of reverting a few commits which caused all these
> > problems if fixing them all during rc cycle seems not possible? I
> > haven't bisected them yet, rather concentrated on providing fixes, but I
> > can still try to do it, starting back from the original issue
> > (http://www.spinics.net/lists/linux-omap/msg60052.html), if so decided.
>
> We can't revert that because the SRAM init has been moved to later for
> map_io.

Yes, I know that. What I don't know yet is what else should be reverted
to fix the original issue other than applying
e9b7086b80c4d9e354f4edc9e280ae85a60df408, which seems to introduce (or
maybe 'exhibit' is a better word here) more bugs than it fixes.

> But if that patch changed the behaviour on your board, then that's
> the problem we should fix.
>
> If you're now stuck at 60MHz rate, care to see if the following patch
> makes the kernel behave the same way as before for you?
[snip]
>
> --- a/arch/arm/mach-omap1/clock_data.c
> +++ b/arch/arm/mach-omap1/clock_data.c
> @@ -927,7 +927,7 @@ int __init omap1_clk_init(void)
>
> void __init omap1_clk_late_init(void)
> {
> - if (ck_dpll1.rate >= OMAP1_DPLL1_SANE_VALUE)
> + if (ck_dpll1.rate > OMAP1_DPLL1_SANE_VALUE)
> return;
>
> /* Find the highest supported frequency and enable it */

This change really makes sense to me, however, knowing the initial
(bootloader selected) clock rate my board boots at, which is
unfortunately raw 12 MHz, I would be surprised if that helped.

Before e9b7086b80c4d9e354f4edc9e280ae85a60df408,
omap1_select_table_rate() was returning the rate selected with .config
because it was called early, with ck_dpll1_p->rate uninitialized. Now it
is not, and returns nothing, resulting in 60 MHz default. Then, the only
way I can see to correct the problem is something like patch 3/5, which
you are justifiably affraid of of always switching to 216 MHz with
omap1_defconfig.

Thanks,
Janusz
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/