From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: ksummit-discuss@lists.linuxfoundation.org, "Nikula,
Jani" <jani.nikula@linux.intel.com>,
Dave Airlie <airlied@linux.ie>,
Grant Likely <grant.likely@linaro.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [Ksummit-discuss] [CORE TOPIC] (group) maintainership models
Date: Tue, 2 Aug 2016 09:41:36 +0100 [thread overview]
Message-ID: <20160802084136.GF1041@n2100.armlinux.org.uk> (raw)
In-Reply-To: <2ddeb98b-7bf8-aa21-2dee-9e02f9c59a92@ti.com>
On Tue, Aug 02, 2016 at 09:48:53AM +0300, Peter Ujfalusi wrote:
> I'm not going to move the legacy API under dmaengine, it makes no sense.
>
> My plan is to do what I did with the eDMA driver stack:
> - convert drivers using the legacy API to dmaengine
> - 'merge' the code from plat-omap to the dmaengine driver
> - while doing this the legacy API will vanish along with the plat-omap/dma.c
>
> As with the eDMA, the sDMA stack will need some cleanup, but the good
> thing is that the dmaengine driver have minimal dependency on the legacy
> plat-omap/dma.c API.
I totally oppose moving arch/arm/plat-omap/dma.c into drivers/dma.
The omap-dma driver in drivers/dma is a replacement modern driver
for the legacy crap, and most users of the legacy crap have been
converted.
Why we still have users of the legacy crap is because:
(a) they don't fit into the DMA engine API very well
(b) I don't have hardware to be able to test them
and, because of that, I'm not going to start proposing DMA engine API
extensions to support something that I've no way to even test.
I've asked for help from TI on this when I was woring on the DMA
engine implementation, and there was no interest - it kept being
put back on me as something for me to sort. It became an impossible
situation.
So, how things were left was that I'd introduce a warning into the
legacy driver, and in a few years time we'd strip it out of users
and delete the legacy driver.
The warning (which is rather large, because it's a WARN(), so
involves a kernel stack dump) has not produced (afaik) any complaints
from anyone. So, we can probably conclude that any of these drivers
which are using the legacy DMA code are probably not being used.
This means we can save ourselves a lot of work and just delete all
these drivers using the legacy OMAP DMA along with the legacy OMAP
DMA driver.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
next prev parent reply other threads:[~2016-08-02 8:41 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-20 12:11 [Ksummit-discuss] [CORE TOPIC] (group) maintainership models Daniel Vetter
2016-07-22 20:02 ` Darren Hart
2016-07-25 5:57 ` Daniel Vetter
2016-07-26 16:22 ` Darren Hart
2016-07-28 22:13 ` Bjorn Helgaas
2016-07-26 16:45 ` Olof Johansson
2016-07-27 3:04 ` Vinod Koul
2016-07-27 5:34 ` Wolfram Sang
2016-07-27 7:53 ` Arnd Bergmann
2016-07-27 12:57 ` Vinod Koul
2016-07-27 14:22 ` Mark Brown
2016-07-27 17:15 ` Vinod Koul
2016-07-28 8:44 ` Arnd Bergmann
2016-07-28 23:48 ` Alexandre Belloni
2016-07-29 0:06 ` Stephen Rothwell
2016-07-31 17:57 ` Vinod Koul
2016-08-01 6:56 ` Arnd Bergmann
2016-08-01 7:36 ` Laurent Pinchart
2016-08-01 14:10 ` Arnd Bergmann
2016-08-02 4:46 ` Vinod Koul
2016-08-02 6:48 ` Peter Ujfalusi
2016-08-02 7:27 ` Arnd Bergmann
2016-08-02 8:29 ` Peter Ujfalusi
2016-08-02 8:33 ` Laurent Pinchart
2016-08-02 9:49 ` Tony Lindgren
2016-08-02 8:41 ` Russell King - ARM Linux [this message]
2016-08-02 9:21 ` Laurent Pinchart
2016-08-02 9:27 ` Russell King - ARM Linux
2016-09-02 10:46 ` Vinod Koul
2016-09-02 17:25 ` Linus Torvalds
2016-09-02 20:06 ` Arnd Bergmann
2016-09-02 20:26 ` Linus Torvalds
2016-09-02 20:26 ` Linus Torvalds
2016-09-02 20:43 ` Julia Lawall
2016-09-02 20:43 ` Julia Lawall
2016-09-02 20:50 ` Linus Torvalds
2016-09-02 20:50 ` Linus Torvalds
2016-09-02 22:16 ` Benjamin Herrenschmidt
2016-09-02 22:16 ` Benjamin Herrenschmidt
2016-09-03 14:02 ` Michael Ellerman
2016-09-03 14:02 ` Michael Ellerman
2016-09-02 23:35 ` Arnd Bergmann
2016-09-04 17:45 ` Geert Uytterhoeven
2016-09-04 17:59 ` Linus Torvalds
2016-09-03 0:07 ` Mark Brown
2016-07-27 12:59 ` Daniel Vetter
2016-07-27 13:03 ` Daniel Vetter
2016-08-01 14:42 ` Jani Nikula
2016-09-07 5:03 Leon Romanovsky
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