RE: [PATCH v6 01/26] ARM: shmobile: Add watchdog support

[Fabrizio Castro]

Hi Geert,

> Subject: Re: [PATCH v6 01/26] ARM: shmobile: Add watchdog support
>
> Hi Fabrizio,
>
> On Wed, Feb 28, 2018 at 6:40 PM, Fabrizio Castro
> <fabrizio.cas...@bp.renesas.com> wrote:
> > On R-Car Gen2 and RZ/G1 platforms, we use the SBAR registers to make non
> > boot CPUs run a routine designed to bring up SMP and deal with hot plug.
> > The value contained in the SBAR registers is not initialized by a WDT
> > triggered reset, which means that after a WDT triggered reset we jump
> > to the SMP bring up routine, preventing the system from executing the
> > bootrom code.
> >
> > The purpose of this patch is to jump to the bootrom code in case of a
> > WDT triggered reset, and keep the SMP functionality untouched.
> > In order to tell if the code had been called due to the WDT overflowing
> > we are testing WOVF from register RWTCSRA.
> >
> > The new function shmobile_boot_vector_gen2 isn't replacing
> > shmobile_boot_vector for backward compatibility reasons. The kernel
> > will install the best option (either shmobile_boot_vector or
> > shmobile_boot_vector_gen2) to ICRAM1 after parsing the device tree,
> > according to the amount of memory available.
> >
> > Since shmobile_boot_vector has become bigger, "reg" property of nodes
> > compatible with "renesas,smp-sram" now need to be set to a value
> > greater or equal to "<0 0x60>".
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.cas...@bp.renesas.com>
> > Signed-off-by: Ramesh Shanmugasundaram 
> > <ramesh.shanmugasunda...@bp.renesas.com>
> > Reviewed-by: Geert Uytterhoeven <geert+rene...@glider.be>
> > ---
> > v5->v6:
> > * taken ifdefs out as per Geert's suggestion.
>
> My intention was to remove the #ifdefs from the header file only, not
> from arch/arm/mach-shmobile/headsmp.S, as the latter is used for
> other SoC families, too.

Ah ok, I'll send another version to restore the ifdef within headsmp.S then.

Thanks,
Fab

>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- 
> ge...@linux-m68k.org
>
> 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



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Re: [PATCH v6 01/26] ARM: shmobile: Add watchdog support

[Geert Uytterhoeven]

Hi Fabrizio,

On Wed, Feb 28, 2018 at 6:40 PM, Fabrizio Castro
 wrote:
> On R-Car Gen2 and RZ/G1 platforms, we use the SBAR registers to make non
> boot CPUs run a routine designed to bring up SMP and deal with hot plug.
> The value contained in the SBAR registers is not initialized by a WDT
> triggered reset, which means that after a WDT triggered reset we jump
> to the SMP bring up routine, preventing the system from executing the
> bootrom code.
>
> The purpose of this patch is to jump to the bootrom code in case of a
> WDT triggered reset, and keep the SMP functionality untouched.
> In order to tell if the code had been called due to the WDT overflowing
> we are testing WOVF from register RWTCSRA.
>
> The new function shmobile_boot_vector_gen2 isn't replacing
> shmobile_boot_vector for backward compatibility reasons. The kernel
> will install the best option (either shmobile_boot_vector or
> shmobile_boot_vector_gen2) to ICRAM1 after parsing the device tree,
> according to the amount of memory available.
>
> Since shmobile_boot_vector has become bigger, "reg" property of nodes
> compatible with "renesas,smp-sram" now need to be set to a value
> greater or equal to "<0 0x60>".
>
> Signed-off-by: Fabrizio Castro 
> Signed-off-by: Ramesh Shanmugasundaram 
> 
> Reviewed-by: Geert Uytterhoeven 
> ---
> v5->v6:
> * taken ifdefs out as per Geert's suggestion.

My intention was to remove the #ifdefs from the header file only, not
from arch/arm/mach-shmobile/headsmp.S, as the latter is used for
other SoC families, too.

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

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

Re: [PATCH v6 01/26] ARM: shmobile: Add watchdog support

[Simon Horman]

On Wed, Feb 28, 2018 at 05:40:22PM +, Fabrizio Castro wrote:
> On R-Car Gen2 and RZ/G1 platforms, we use the SBAR registers to make non
> boot CPUs run a routine designed to bring up SMP and deal with hot plug.
> The value contained in the SBAR registers is not initialized by a WDT
> triggered reset, which means that after a WDT triggered reset we jump
> to the SMP bring up routine, preventing the system from executing the
> bootrom code.
> 
> The purpose of this patch is to jump to the bootrom code in case of a
> WDT triggered reset, and keep the SMP functionality untouched.
> In order to tell if the code had been called due to the WDT overflowing
> we are testing WOVF from register RWTCSRA.
> 
> The new function shmobile_boot_vector_gen2 isn't replacing
> shmobile_boot_vector for backward compatibility reasons. The kernel
> will install the best option (either shmobile_boot_vector or
> shmobile_boot_vector_gen2) to ICRAM1 after parsing the device tree,
> according to the amount of memory available.
> 
> Since shmobile_boot_vector has become bigger, "reg" property of nodes
> compatible with "renesas,smp-sram" now need to be set to a value
> greater or equal to "<0 0x60>".
> 
> Signed-off-by: Fabrizio Castro 
> Signed-off-by: Ramesh Shanmugasundaram 
> 

Thanks, I have marked this as deferred as I would like dependencies to
be merged first.