Hi Wolfram,
On Mon, Feb 22, 2016 at 3:10 PM, Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
> From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
>
> This reverts commit 406663ed61c8ad2b792824af1c1bc0e4faa711c6. With
> BPREDICT enabled, my Lager board can't boot anymore and gets stuck
> early in the boot process (mostly without any printout, sometimes with a
> little printout)
And it just stops without printing anything special?
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
I suspect you're bitten by the issue from "RCU lockup? (was: Re: [PATCH v2
tip/core/rcu 10/14] rcu: Don't redundantly disable irqs in
rcu_irq_{enter,exit}())" (http://www.spinics.net/lists/kernel/msg2167464.html).
At one point, I also thought it was related to CONFIG_CPU_BPREDICT_DISABLE,
but then I managed to reproduce the issue with that option disabled.
I suspect the issue is just more likely to happen with
CONFIG_CPU_BPREDICT_DISABLE=y.
Does it help if you add a function
void filler(void)
{
asm("nop");
asm("nop");
}
to a file under arch/arm/mach-shmobile/?
What I saw was that the failure mode depends on the number of NOPs.
Sometimes it hangs early, sometimes it continues and hangs later,
sometimes it works reliably.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
