From: Tony Prisk <linux@prisktech.co.nz>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robherring2@gmail.com>,
Arm Kernel Mailing List <linux-arm-kernel@lists.infradead.org>,
mgorman@suse.de, linux-mm@kvack.org
Subject: Re: dma_alloc_coherent fails in framebuffer
Date: Mon, 15 Oct 2012 09:34:55 +1300 [thread overview]
Message-ID: <1350246895.11504.6.camel@gitbox> (raw)
In-Reply-To: <1350192523.10946.4.camel@gitbox>
On Sun, 2012-10-14 at 18:28 +1300, Tony Prisk wrote:
> Up until 07 Oct, drivers/video/wm8505-fb.c was working fine, but on the
> 11 Oct when I did another pull from linus all of a sudden
> dma_alloc_coherent is failing to allocate the framebuffer any longer.
>
> I did a quick look back and found this:
>
> ARM: add coherent dma ops
>
> arch_is_coherent is problematic as it is a global symbol. This
> doesn't work for multi-platform kernels or platforms which can support
> per device coherent DMA.
>
> This adds arm_coherent_dma_ops to be used for devices which connected
> coherently (i.e. to the ACP port on Cortex-A9 or A15). The arm_dma_ops
> are modified at boot when arch_is_coherent is true.
>
> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
>
>
> This is the only patch lately that I could find (not that I would claim
> to be any good at finding things) that is related to the problem. Could
> it have caused the allocations to fail?
>
> Regards
> Tony P
Have done a bit more digging and found the cause - not Rob's patch so
apologies.
The cause of the regression is this patch:
next parent reply other threads:[~2012-10-14 20:34 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1350192523.10946.4.camel@gitbox>
2012-10-14 20:34 ` Tony Prisk [this message]
2012-10-14 22:26 ` dma_alloc_coherent fails in framebuffer Tony Prisk
2012-10-15 6:42 ` Tomasz Figa
2012-10-15 8:03 ` Tony Prisk
2012-10-15 13:35 ` Marek Szyprowski
2012-10-15 9:45 ` Mel Gorman
2012-10-15 18:28 ` Tony Prisk
2012-10-16 2:17 ` Bob Liu
2012-10-16 5:02 ` Tony Prisk
2012-10-16 5:54 ` Tony Prisk
2012-10-16 6:50 ` Tony Prisk
2012-10-16 7:58 ` Mel Gorman
2012-10-16 8:13 ` Tony Prisk
2012-10-16 14:41 ` James Bottomley
2012-10-17 2:26 ` Bob Liu
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