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From: tony@atomide•com (Tony Lindgren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] ARM: omap2+: Revert omap-smp.c changes resetting cpu1 during boot
Date: Tue, 14 Feb 2017 11:36:45 -0800	[thread overview]
Message-ID: <20170214193645.GM21809@atomide.com> (raw)
In-Reply-To: <20170213215013.19929-1-tony@atomide.com>

* Tony Lindgren <tony@atomide•com> [170213 13:51]:
> Commit 3251885285e1 ("ARM: OMAP4+: Reset CPU1 properly for kexec") started
> resetting cpu1 because of a kexec boot issue I was seeing earlier in 2016
> on omap4 when doing kexec boot between two different kernel versions. The
> booted kernel ended up trying to use the old kernel start-up address unless
> cpu1 was reset before configuring the cpu1 start-up address.
> 
> It seems the reset part was not correct but probably working around some
> other issue. I have not been able to reproduce this issue any longer despite
> testing with backported patches back to v4.6 kernel. So it is possible this
> issue was caused by other work in progress kexec patches I had applied. Or
> it is possible some other fixes have made the issue go way.
> 
> The unconditional reset of cpu1 can cause issues booting some devices. For
> example, bootloader configured secure OS running on cpu1 will fail as the
> configuration is not preserved as reported by Andrew F. Davis <afd@ti•com>.
> 
> Let's fix the issue by reverting the cpu1 reset parts. If it turns out we
> still need to reset cpu1 in some cases, we can add it back and do it
> conditionally.

Actually with this I'm now seeing cpu1 not come up after a suspend/resume
cycle on duovero:

[  118.257415] CPU1: shutdown
[  118.294616] Error taking CPU1 up: -2
[  118.299072] PM: noirq resume of devices complete after 3.723 msecs
[  118.303802] PM: early resume of devices complete after 3.723 msecs

So this issue needs to be investigated more.

Regards,

Tony

> Fixes: 3251885285e1 ("ARM: OMAP4+: Reset CPU1 properly for kexec")
> Cc: Keerthy <j-keerthy@ti•com>
> Cc: Tero Kristo <t-kristo@ti•com>
> Reported-by: Andrew F. Davis <afd@ti•com>
> Signed-off-by: Tony Lindgren <tony@atomide•com>
> ---
>  arch/arm/mach-omap2/omap-smp.c | 10 ----------
>  1 file changed, 10 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/omap-smp.c b/arch/arm/mach-omap2/omap-smp.c
> --- a/arch/arm/mach-omap2/omap-smp.c
> +++ b/arch/arm/mach-omap2/omap-smp.c
> @@ -300,16 +300,6 @@ static void __init omap4_smp_prepare_cpus(unsigned int max_cpus)
>  		scu_enable(cfg.scu_base);
>  
>  	/*
> -	 * Reset CPU1 before configuring, otherwise kexec will
> -	 * end up trying to use old kernel startup address.
> -	 */
> -	if (cfg.cpu1_rstctrl_va) {
> -		writel_relaxed(1, cfg.cpu1_rstctrl_va);
> -		readl_relaxed(cfg.cpu1_rstctrl_va);
> -		writel_relaxed(0, cfg.cpu1_rstctrl_va);
> -	}
> -
> -	/*
>  	 * Write the address of secondary startup routine into the
>  	 * AuxCoreBoot1 where ROM code will jump and start executing
>  	 * on secondary core once out of WFE
> -- 
> 2.11.1
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

  reply	other threads:[~2017-02-14 19:36 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-13 21:50 [PATCH] ARM: omap2+: Revert omap-smp.c changes resetting cpu1 during boot Tony Lindgren
2017-02-14 19:36 ` Tony Lindgren [this message]
2017-02-15 18:39   ` Tony Lindgren
2017-02-15 19:12     ` Tony Lindgren
2017-02-15 22:13       ` Andrew F. Davis
2017-02-15 22:27         ` Tony Lindgren
2017-02-16 16:10           ` Tony Lindgren
2017-02-16 16:21             ` Tony Lindgren
2017-02-16 16:29             ` Andrew F. Davis
2017-02-16 16:54               ` Tony Lindgren
2017-02-16 19:07                 ` Tony Lindgren
2017-02-17 15:55                   ` Tony Lindgren
2017-02-17 20:27                     ` Andrew F. Davis
2017-02-17 21:09                       ` Tony Lindgren
  -- strict thread matches above, loose matches on Subject: below --
2017-03-13 20:52 [PATCH] ARM: omap2+: Revert omap-smp.c changes resetting CPU1 " Tony Lindgren
2017-03-13 21:28 ` Andrew F. Davis
2017-03-13 21:47   ` Tony Lindgren
2017-03-14  7:30 ` Tero Kristo
2017-03-14 15:17   ` Tony Lindgren
2017-03-14 16:02     ` Andrew F. Davis
2017-03-14 16:41       ` Tony Lindgren
2017-03-14 17:57         ` Andrew F. Davis
2017-03-14 18:14           ` Tony Lindgren
2017-03-15 17:22             ` Tony Lindgren
2017-03-16 15:29               ` Tony Lindgren
2017-03-17  9:24                 ` Russell King - ARM Linux
2017-03-17 13:57                   ` Tony Lindgren
2017-03-17 16:25                     ` Andrew F. Davis
2017-03-22 17:57                       ` Tony Lindgren

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