From: nicolas.ferre@atmel•com (Nicolas Ferre)
To: linux-arm-kernel@lists•infradead.org
Subject: arm926_dma_flush_range undefined!
Date: Tue, 11 May 2010 15:32:04 +0200 [thread overview]
Message-ID: <4BE95C54.5070008@atmel.com> (raw)
In-Reply-To: <20100511094448.GB18828@n2100.arm.linux.org.uk>
Le 11/05/2010 11:44, Russell King - ARM Linux :
> On Tue, May 11, 2010 at 11:43:17AM +0200, Nicolas Ferre wrote:
>> Le 06/05/2010 19:59, Russell King - ARM Linux :
>>> On Thu, May 06, 2010 at 03:07:11PM +0100, Catalin Marinas wrote:
>>>> On Thu, 2010-05-06 at 15:11 +0200, Nicolas Ferre wrote:
>>>>> I am trying to compile a recent kernel
>>>>> (v2.6.34-rc6-201-g722154e) and I am
>>>>> having this kind of error:
>>>>>
>>>>> ERROR: "arm926_dma_flush_range" [drivers/mmc/host/at91_mci.ko] undefined!
>>>>
>>>> The driver seems to use dmac_flush_range() directly. That's not part of
>>>> the DMA API. Could you not use one of the supported DMA API functions?
>>
>> The difficult part for me is to choose the proper one ;-)
>>
>> And also, I am wondering if this call is needed as we do a
>> kunmap_atomic() on the same scatterlist pointer just before. Does not
>> kunmap_atomic() embed a cache flushing directive already?
>
> No it doesn't. What are you trying to do here?
After a read with DMA from sd/mmc interface, a DMA buffer allocated by
dma_alloc_coherent() is filled.
This buffer is then copied to the scatterlist provided by the mmc
request (from drivers/mmc/card/block.c it seems that sg buffers are
alocacted via kmalloc()).
For each buffer of the scatterlist, I do this dmac_flush_rage()...
As copy is done between a coherent and a kernel memory buffers, I guess
that the flushing routine is not needed?
Best regards,
--
Nicolas Ferre
next prev parent reply other threads:[~2010-05-11 13:32 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-06 13:11 arm926_dma_flush_range undefined! Nicolas Ferre
2010-05-06 14:07 ` Catalin Marinas
2010-05-06 17:59 ` Russell King - ARM Linux
2010-05-11 9:43 ` Nicolas Ferre
2010-05-11 9:44 ` Russell King - ARM Linux
2010-05-11 13:32 ` Nicolas Ferre [this message]
2010-05-11 13:44 ` Russell King - ARM Linux
2010-05-11 17:09 ` [PATCH] MMC: at91_mci: modify cache flush routines Nicolas Ferre
2010-05-12 21:19 ` Andrew Morton
2010-05-12 21:30 ` Russell King - ARM Linux
2010-05-19 11:04 ` Nicolas Ferre
2010-05-12 11:18 ` arm926_dma_flush_range undefined! Catalin Marinas
2010-05-12 18:42 ` Russell King - ARM Linux
2010-05-12 21:39 ` Catalin Marinas
2010-05-12 6:48 ` Wolfgang Mües
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4BE95C54.5070008@atmel.com \
--to=nicolas.ferre@atmel$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox