From: nicolas.ferre@atmel.com (Nicolas Ferre)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 2/2] Documentation: dmaengine: Add a documentation for the dma controller API
Date: Thu, 9 Oct 2014 16:04:02 +0200 [thread overview]
Message-ID: <543695D2.1090504@atmel.com> (raw)
In-Reply-To: <CAMuHMdUKk1kJwBndjiziRexOtXV-FN7568YJ9K_ZzVecTgmbuw@mail.gmail.com>
On 09/10/2014 15:39, Geert Uytterhoeven :
> On Tue, Oct 7, 2014 at 4:52 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
>>>>> +These various types will also affect how the source and destination
>>>>> +addresses change over time, as DMA_SLAVE transfers will usually have
>>>>> +one of the addresses that will increment, while the other will not,
>>>>> +DMA_CYCLIC will have one address that will loop, while the other, will
>>>>
>>>> s/the other,/the other/
>>>>
>>>>> +not change, etc.
>>>
>>> This is a little bit vague in my opinion. And usually, it is pretty
>>> implementation specific.
>>
>> Which is why we can't really be more precise. If you have any other
>> wording coming to your mind, I'm all for it :)
>
> Perhaps:
>
> Addresses pointing to RAM are typically incremented (or decremented) after
> each transfer. In case of a ring buffer, they may loop (DMA_CYCLIC).
> Addresses pointing to a device's register (e.g. a FIFO) are typically fixed.
+1 ;-)
Bye,
--
Nicolas Ferre
WARNING: multiple messages have this Message-ID (diff)
From: Nicolas Ferre <nicolas.ferre@atmel.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>,
Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: "Russell King" <linux@arm.linux.org.uk>,
"Vinod Koul" <vinod.koul@intel.com>,
"Laurent Pinchart" <laurent.pinchart@ideasonboard.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
dmaengine@vger.kernel.org, "Arnd Bergmann" <arnd@arndb.de>,
"Antoine Ténart" <antoine@free-electrons.com>,
"Thomas Petazzoni" <thomas@free-electrons.com>,
"Alexandre Belloni" <alexandre.belloni@free-electrons.com>,
"Boris Brezillon" <boris@free-electrons.com>,
"Matt Porter" <matt.porter@linaro.org>,
"Gregory Clement" <gregory.clement@free-electrons.com>
Subject: Re: [PATCH v2 2/2] Documentation: dmaengine: Add a documentation for the dma controller API
Date: Thu, 9 Oct 2014 16:04:02 +0200 [thread overview]
Message-ID: <543695D2.1090504@atmel.com> (raw)
In-Reply-To: <CAMuHMdUKk1kJwBndjiziRexOtXV-FN7568YJ9K_ZzVecTgmbuw@mail.gmail.com>
On 09/10/2014 15:39, Geert Uytterhoeven :
> On Tue, Oct 7, 2014 at 4:52 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
>>>>> +These various types will also affect how the source and destination
>>>>> +addresses change over time, as DMA_SLAVE transfers will usually have
>>>>> +one of the addresses that will increment, while the other will not,
>>>>> +DMA_CYCLIC will have one address that will loop, while the other, will
>>>>
>>>> s/the other,/the other/
>>>>
>>>>> +not change, etc.
>>>
>>> This is a little bit vague in my opinion. And usually, it is pretty
>>> implementation specific.
>>
>> Which is why we can't really be more precise. If you have any other
>> wording coming to your mind, I'm all for it :)
>
> Perhaps:
>
> Addresses pointing to RAM are typically incremented (or decremented) after
> each transfer. In case of a ring buffer, they may loop (DMA_CYCLIC).
> Addresses pointing to a device's register (e.g. a FIFO) are typically fixed.
+1 ;-)
Bye,
--
Nicolas Ferre
next prev parent reply other threads:[~2014-10-09 14:04 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-26 15:40 [PATCH v2 1/2] Documentation: dmaengine: Move the current doc to a folder of its own Maxime Ripard
2014-09-26 15:40 ` Maxime Ripard
2014-09-26 15:40 ` [PATCH v2 2/2] Documentation: dmaengine: Add a documentation for the dma controller API Maxime Ripard
2014-09-26 15:40 ` Maxime Ripard
2014-09-26 18:04 ` Randy Dunlap
2014-09-26 18:04 ` Randy Dunlap
2014-10-07 16:48 ` Maxime Ripard
2014-10-07 16:48 ` Maxime Ripard
2014-10-06 12:09 ` Laurent Pinchart
2014-10-06 12:09 ` Laurent Pinchart
2014-10-07 12:16 ` Nicolas Ferre
2014-10-07 12:16 ` Nicolas Ferre
2014-10-07 14:52 ` Maxime Ripard
2014-10-07 14:52 ` Maxime Ripard
2014-10-07 15:05 ` Laurent Pinchart
2014-10-07 15:05 ` Laurent Pinchart
2014-10-08 12:19 ` Vinod Koul
2014-10-08 12:19 ` Vinod Koul
2014-10-09 8:56 ` Laurent Pinchart
2014-10-09 8:56 ` Laurent Pinchart
2014-10-08 12:07 ` Vinod Koul
2014-10-08 12:07 ` Vinod Koul
2014-10-09 13:39 ` Geert Uytterhoeven
2014-10-09 13:39 ` Geert Uytterhoeven
2014-10-09 14:04 ` Nicolas Ferre [this message]
2014-10-09 14:04 ` Nicolas Ferre
2014-10-17 11:23 ` Maxime Ripard
2014-10-17 11:23 ` Maxime Ripard
2014-10-22 20:08 ` Laurent Pinchart
2014-10-22 20:08 ` Laurent Pinchart
2014-09-28 15:57 ` [PATCH v2 1/2] Documentation: dmaengine: Move the current doc to a folder of its own Vinod Koul
2014-09-28 15:57 ` Vinod Koul
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