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From: Wei Ni <wni@nvidia.com>
To: Rob Herring <robherring2@gmail.com>, <ccross@android.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	<keescook@chromium.org>, <cbouatmailru@gmail.com>,
	<tony.luck@intel.com>
Subject: Re: [RFC PATCH 1/3] pstore-ram: use write-combine mappings
Date: Wed, 19 Jun 2013 19:22:45 +0800	[thread overview]
Message-ID: <51C19485.3000708@nvidia.com> (raw)

> Atomic operations are undefined behavior on ARM for device or strongly
> ordered memory types. So use write-combine variants for mappings. This
> corresponds to normal, non-cacheable memory on ARM. For many other
> architectures, this change should not change the mapping type.

Hi, all
I have met this problems on tegra soc.
I tried to use pstore-ram, but the system will hang up when run the
atomic_cmpxchg() in the buffer_start_add() or buffer_size_add(),
whatever I use iomapped or vmapped regions.

I tried to apply this patch set, it was failed with vmap, but if use
iomapped rgiions, the ldrex/strex can work on this memory, and the
ramoops driver can work.

Does there have any updates for this issue?
Or how can I debug it?

Thanks.
Wei.

             reply	other threads:[~2013-06-19 11:22 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-19 11:22 Wei Ni [this message]
  -- strict thread matches above, loose matches on Subject: below --
2013-04-10  3:08 [RFC PATCH 1/3] pstore-ram: use write-combine mappings Rob Herring
2013-04-10  3:53 ` Colin Cross
2013-04-10 13:30   ` Rob Herring
2013-04-15 22:21     ` Colin Cross
2013-04-15 23:59       ` Rob Herring
2013-04-16  0:43         ` Colin Cross
2013-04-16  8:44           ` Will Deacon
2013-04-16 12:58             ` Rob Herring
2013-04-16 13:48               ` Catalin Marinas
2013-04-19  9:54   ` Russell King - ARM Linux

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