From: linus.ml.walleij@gmail.com (Linus Walleij)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: add PrimeCell generic DMA to MMCI/PL180 v10
Date: Thu, 12 Aug 2010 17:58:23 +0200 [thread overview]
Message-ID: <AANLkTike7O_JDXdURqi1186WW26ShD3UutEGSYneRo88@mail.gmail.com> (raw)
In-Reply-To: <20100812143002.GA31982@n2100.arm.linux.org.uk>
2010/8/12 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> On Thu, Aug 12, 2010 at 03:58:08PM +0200, Linus Walleij wrote:
>> In arch/arm/mm/dma-mapping.c
>> dma_map_sg() returns 0 on a mapping error, and the same as
>> passed in the third parameter on success.
>
> Rabin is right - dma_map_sg() is allowed to return fewer entries than
> was passed as it is allowed to coalesce entries together. ?Please don't
> use the implementation as a source of how things should behave, instead
> read the documentation in Documentation/DMA-API.txt:
Aha yeah I get it now, I will take that as tonights reading excercise,
And it makes perfect sense too.
I seem to be in bad company, a quick search in LXR reveals
numerous instances of this error throughout the kernel tree I'll
put it on my TODO list to fix a few of them up.
Yours,
Linus Walleij
prev parent reply other threads:[~2010-08-12 15:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-10 15:32 [PATCH] ARM: add PrimeCell generic DMA to MMCI/PL180 v10 Linus Walleij
2010-08-11 14:48 ` Rabin Vincent
2010-08-12 13:58 ` Linus Walleij
2010-08-12 14:30 ` Russell King - ARM Linux
2010-08-12 15:58 ` Linus Walleij [this message]
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