Message-ID: <54A1BF89.70709@linaro.org>
Date: Mon, 29 Dec 2014 21:54:33 +0100
From: Daniel Lezcano <daniel.lezcano@linaro.org>
User-Agent: Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Thunderbird/31.3.0
MIME-Version: 1.0
To: Mark Rutland <mark.rutland@arm.com>,
        Christoffer Dall <christoffer.dall@linaro.org>, arnd@arndb.de
CC: Marc Zyngier <Marc.Zyngier@arm.com>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Catalin Marinas <Catalin.Marinas@arm.com>,
        Olof Johansson <olof@lixom.net>,
        Yingjoe Chen <yingjoe.chen@mediatek.com>,
        Sonny Rao <sonnyrao@chromium.org>
Subject: Re: [PATCH] clocksource: arch_timer: Fix arm64 platforms not booting
References: <1419776431-26217-1-git-send-email-christoffer.dall@linaro.org> <71346397bb3c0e654aa5b634328ae29c@www.loen.fr> <20141229083509.GC29460@cbox> <20141229191357.GA21793@leverpostej>
In-Reply-To: <20141229191357.GA21793@leverpostej>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org

On 12/29/2014 08:13 PM, Mark Rutland wrote:
> [Adding Arnd]
>
> On Mon, Dec 29, 2014 at 08:35:09AM +0000, Christoffer Dall wrote:
>> On Sun, Dec 28, 2014 at 09:46:20PM +0000, Marc Zyngier wrote:
>>> On 2014-12-28 14:20, Christoffer Dall wrote:
>>>> Commit 0b46b8a718c6e ("clocksource: arch_timer: Fix code to...")
>>>> fixes
>>>> timer issues with certain ARMv7 platforms, but unfortunately breaks
>>>> arm64 platforms with hyp mode (EL2) enabled.
>>>>
>>>> The commit only sets arch_timer_use_virtual to false under
>>>> CONFIG_ARM,
>>>> but forgets that the config variable is also set in other code paths
>>>> (actually, right underneath the check in the patch) with detrimental
>>>> consequences as we've now introduced a direct early call to BUG() on
>>>> practically all arm64 platforms.
>>>>
>>>> One could argue that this code could be refactored to use different
>>>> variables for checking which *timer* to use and which *counter* to
>>>> use,
>>>> which seems to be the desired difference between ARM and arm64 in
>>>> this
>>>> case, but this approach fixes an urgent issue for now.
>>>>
>>>> Cc: Sonny Rao <sonnyrao@chromium.org>
>>>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>>>> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
>>>> Cc: Olof Johansson <olof@lixom.net>
>>>> Cc: Mark Rutland <mark.rutland@arm.com>
>>>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>>>> Cc: Marc Zyngier <marc.zyngier@arm.com>
>>>> Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
>>>> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
>>>> ---
>>>> This was apparently already discovered by Yingjoe Chen in this thread
>>>> https://lkml.org/lkml/2014/11/24/41 and Catalin recommended a similar
>>>> fix.
>>>
>>> I'm increasingly worried about the time it takes to get such critical
>>> fixes into the tree (arm64 is *dead* without it).
>>>
>>> What is holding this patch which, as far as I remember, has been posted
>>> by Catalin almost three weeks ago?
>>>
>> I didn't find that since I didn't think I'd have to go back that long on
>> lakml for something that breaks boot of an entire architecture.  Sorry
>> for the confusion of a second patch, but fwiw, I now spent another few
>> hours bisecting this, so I would really like to see this fix go into
>> mainline ASAP as well to save others the trouble.
>
> Last I knew, Arnd was going to take the fix [1], which has been in
> arm-soc's for-next and fixes branches for almost two weeks now. It
> didn't make it into the last pull req due to some confusion over who was
> going to take it.

I asked arm-soc team to take the fix because it was depending on a patch 
which was already in their tree [1].

Merry Christmas

   -- Daniel

[1] http://www.spinics.net/lists/arm-kernel/msg385704.html

> Arnd, what's the plan for getting this into mainline ASAP?
>
> Mark.
>
> [1] https://git.kernel.org/cgit/linux/kernel/git/arm/arm-soc.git/commit/?h=fixes&id=d6ad36913083d683aad4e02e53580c995f1a6ede
>


-- 
  <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/