From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Subject: Re: [PATCH] ARM: dts: r8a7794: add SMP support Date: Thu, 23 Jun 2016 10:11:04 +0200 Message-ID: References: <14666252.G84Ipxe6EL@wasted.cogentembedded.com> <27171008.uuY7altQup@wasted.cogentembedded.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: Sender: linux-renesas-soc-owner@vger.kernel.org To: Sergei Shtylyov Cc: Simon Horman , linux-renesas-soc@vger.kernel.org, Rob Herring , Mark Rutland , "devicetree@vger.kernel.org" , Russell King , Magnus Damm , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org Hi Sergei, On Wed, Jun 22, 2016 at 12:20 PM, Geert Uytterhoeven wrote: > On Wed, Jun 22, 2016 at 12:08 PM, Sergei Shtylyov > wrote: >> On 6/22/2016 10:20 AM, Geert Uytterhoeven wrote: >> >>>> Add the device tree node for the Advanced Power Management Unit (APMU). >>>> Use the "enable-method" prop to point out that the APMU should be used >>>> for the SMP support. >>>> >>>> Signed-off-by: Sergei Shtylyov >>> >>> >>> Reviewed-by: Geert Uytterhoeven >>> >>>> SMP/PM basically works but you can't offline CPU0 (system hangs)... >>> >>> >>> On #renesas-soc you said it hangs on SILK only, and succeeds on Porter, >>> with a WARNING in the clk core (which one?) during suspend? >> >> Porter is based on R8A7791 (WARNING seemed to be caused by the CAN >> driver). :-) > > Oh right, mixing up boards. > > Will try on (remote) ALT when I find some time... The second CPU boots (irrespective of MD21 setting), but the kernel starts spewing: clocksource: Switched to clocksource arch_sys_counter WARNING: Underflow in clocksource 'arch_sys_counter' observed, time update ignored. Please report this, consider using a different clocksource, if possible. Your kernel is probably still fine. WARNING: Underflow in clocksource 'arch_sys_counter' observed, time update ignored. Please report this, consider using a different clocksource, if possible. Your kernel is probably still fine. Seems like the secondary CPU also needs CNTVOFF initialization, which is done in the BSP in arch/arm/mach-shmobile/headsmp.S. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: geert@linux-m68k.org (Geert Uytterhoeven) Date: Thu, 23 Jun 2016 10:11:04 +0200 Subject: [PATCH] ARM: dts: r8a7794: add SMP support In-Reply-To: References: <14666252.G84Ipxe6EL@wasted.cogentembedded.com> <27171008.uuY7altQup@wasted.cogentembedded.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Sergei, On Wed, Jun 22, 2016 at 12:20 PM, Geert Uytterhoeven wrote: > On Wed, Jun 22, 2016 at 12:08 PM, Sergei Shtylyov > wrote: >> On 6/22/2016 10:20 AM, Geert Uytterhoeven wrote: >> >>>> Add the device tree node for the Advanced Power Management Unit (APMU). >>>> Use the "enable-method" prop to point out that the APMU should be used >>>> for the SMP support. >>>> >>>> Signed-off-by: Sergei Shtylyov >>> >>> >>> Reviewed-by: Geert Uytterhoeven >>> >>>> SMP/PM basically works but you can't offline CPU0 (system hangs)... >>> >>> >>> On #renesas-soc you said it hangs on SILK only, and succeeds on Porter, >>> with a WARNING in the clk core (which one?) during suspend? >> >> Porter is based on R8A7791 (WARNING seemed to be caused by the CAN >> driver). :-) > > Oh right, mixing up boards. > > Will try on (remote) ALT when I find some time... The second CPU boots (irrespective of MD21 setting), but the kernel starts spewing: clocksource: Switched to clocksource arch_sys_counter WARNING: Underflow in clocksource 'arch_sys_counter' observed, time update ignored. Please report this, consider using a different clocksource, if possible. Your kernel is probably still fine. WARNING: Underflow in clocksource 'arch_sys_counter' observed, time update ignored. Please report this, consider using a different clocksource, if possible. Your kernel is probably still fine. Seems like the secondary CPU also needs CNTVOFF initialization, which is done in the BSP in arch/arm/mach-shmobile/headsmp.S. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at 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