From mboxrd@z Thu Jan  1 00:00:00 1970
From: tony@atomide.com (Tony Lindgren)
Date: Sun, 11 May 2014 08:55:43 -0700
Subject: omap4-panda-es boot issues with v3.15-rc4
In-Reply-To: <7heh02ms82.fsf@paris.lan>
References: <536B7E44.2040303@ti.com> <7hppjos2w2.fsf@paris.lan>
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 <20140508165558.GB2198@atomide.com>
 <20140508184055.GC2198@atomide.com> <7hha4zsyro.fsf@paris.lan>
 <536C9084.50209@ti.com> <7heh02ms82.fsf@paris.lan>
Message-ID: <20140511155542.GD28266@atomide.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

* Kevin Hilman <khilman@linaro.org> [140509 16:46]:
> Roger Quadros <rogerq@ti.com> writes:
> 
> > Kevin,
> >
> > On 05/09/2014 01:15 AM, Kevin Hilman wrote:
> >> Tony Lindgren <tony@atomide.com> writes:
> >> 
> >> [...]
> >> 
> >>> ..but I think I found the cause for recent hangs on panda, just a wild
> >>> guess based on looking at the recent cpuidle patches after v3.14.
> >>>
> >>> Looks like reverting 0b89e9aa2856 (cpuidle: delay enabling interrupts
> >>> until all coupled CPUs leave idle) makes booting work reliably again
> >>> on panda.
> >>>
> >>> Can you guys confirm, so far no issues here after few boot tests,
> >>> but it might be too early to tell.
> >> 
> >> Reverting that makes things a bit more stable, but it still eventually
> >> fails in the same way.  For me it took 8 boots for it to eventually
> >> fail.
> >> 
> >> However, if I build with CONFIG_CPU_IDLE=n, it becomes much more stable
> >> (20+ boots in a row and still going.)
> >> 
> >
> > Can you please test with CPU_IDLE enabled but C3 disabled as in below patch?
> > It worked for me 10/10 boots.
> 
> Yup, it worked for me too for 10/10 boots in a row.

But what has caused this regression, does it work reliably with let's
say v3.13 or v3.12?

Regards,

Tony