From: Joonyoung Shim <jy0922.shim@samsung.com>
To: Marc Zyngier <maz@misterjones.org>
Cc: dan.j.williams@intel.com, linus.ml.walleij@gmail.com,
kyungmin.park@samsung.com, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] PL330: Add PL330 DMA controller driver
Date: Thu, 25 Mar 2010 18:01:00 +0900 [thread overview]
Message-ID: <4BAB264C.2090502@samsung.com> (raw)
In-Reply-To: <20100325054430.165311fa@taxman.wild-wind.fr.eu.org>
On 3/25/2010 2:44 PM, Marc Zyngier wrote:
> On Thu, 25 Mar 2010 12:17:15 +0900
> Joonyoung Shim <jy0922.shim@samsung.com> wrote:
>
>> +/* instruction set functions */
>> +static inline int pl330_dmaaddh(u8 *desc_pool_virt, u16 imm, bool ra)
>> +{
>> + u8 opcode = DMAADDH | (ra << 1);
>> +
>> + writeb(opcode, desc_pool_virt++);
>
> desc_pool_virt is a virtual address (from dma_alloc_coherent). In such
> case, write[bwl] seems to be the wrong interface. I suggest the
> following code:
>
> *desc_pool_virt++ = opcode;
>
>> + writew(imm, desc_pool_virt);
>
Right. The write[bwl] is api for address ioremapped of io device. I will
change these.
> Does anything ensure that this won't generate an unaligned access?
>
PL330 DMA controller fetches variable length instructions that consist of
one to six bytes, so i think unaligned access is no problem.
>> + return 3;
>> +}
>
> M.
next prev parent reply other threads:[~2010-03-25 9:01 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-25 3:17 [PATCH v2] PL330: Add PL330 DMA controller driver Joonyoung Shim
2010-03-25 5:34 ` jassi brar
2010-03-25 8:30 ` Linus Walleij
2010-03-25 12:17 ` jassi brar
2010-03-25 15:13 ` Dan Williams
2010-03-25 22:27 ` jassi brar
2010-03-25 23:12 ` Dan Williams
2010-03-25 23:59 ` jassi brar
2010-03-26 0:29 ` Kyungmin Park
2010-03-26 0:48 ` jassi brar
2010-03-26 0:54 ` Joonyoung Shim
2010-03-26 1:01 ` jassi brar
2010-03-25 15:20 ` Linus Walleij
2010-03-25 22:36 ` jassi brar
2010-04-01 5:34 ` jassi brar
2010-04-01 23:23 ` Linus Walleij
2010-04-02 1:38 ` jassi brar
2010-04-17 7:06 ` Kyungmin Park
2010-04-19 1:14 ` jassi brar
2010-03-25 5:44 ` Marc Zyngier
2010-03-25 9:01 ` Joonyoung Shim [this message]
2010-03-25 9:32 ` Marc Zyngier
2010-03-25 10:05 ` Joonyoung Shim
2010-03-25 10:32 ` Marc Zyngier
2010-03-25 11:48 ` Joonyoung Shim
2010-03-25 8:26 ` Linus Walleij
2010-03-26 2:08 ` jassi brar
2010-03-31 1:07 ` Ben Dooks
2010-03-31 1:40 ` jassi brar
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