From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: yanjiang.jin@windriver.com
Cc: mark.rutland@arm.com, dinguyen@kernel.org,
dinguyen@opensource.altera.com, jinyanjiang@gmail.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] socfpga_a10: reset CPU1 in socfpga_cpu_kill()
Date: Mon, 15 May 2017 10:55:14 +0100 [thread overview]
Message-ID: <20170515095513.GS22219@n2100.armlinux.org.uk> (raw)
In-Reply-To: <20170515091336.10827-2-yanjiang.jin@windriver.com>
On Mon, May 15, 2017 at 05:13:36PM +0800, yanjiang.jin@windriver.com wrote:
> From: Yanjiang Jin <yanjiang.jin@windriver.com>
>
> socfpga_cpu_die() just puts CPU in WFI, not actually off. So that Kexec's
> second kernel goes wrong since the kerenl text gets ovewritten.
> Now reset CPU1 in cpu_kill() to avoid this error.
> Also add flush_cache_all() to prevent data from being lost in cpu_die().
You should not need this, as the common code does the cache flushing
for you.
It's rather unsafe too - you are completely unsynchronised between the
CPU executing in cpu_die() and the CPU executing cpu_kill() - it's
quite possible for the code in cpu_kill() to take effect when you're
part-way through the flush_cache_all().
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
next prev parent reply other threads:[~2017-05-15 9:55 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-15 9:13 [V2 PATCH] socfpga_a10: fix a kexec boot issue yanjiang.jin
2017-05-15 9:13 ` [PATCH] socfpga_a10: reset CPU1 in socfpga_cpu_kill() yanjiang.jin
2017-05-15 9:55 ` Russell King - ARM Linux [this message]
-- strict thread matches above, loose matches on Subject: below --
2017-05-10 5:13 [PATCH] socfpga_a10: fix a kexec boot issue yanjiang.jin
2017-05-10 5:13 ` [PATCH] socfpga_a10: reset CPU1 in socfpga_cpu_kill() yanjiang.jin
2017-05-12 14:25 ` Dinh Nguyen
2017-05-12 14:36 ` Mark Rutland
2017-05-15 9:05 ` yjin
2017-05-15 10:00 ` Russell King - ARM Linux
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