From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [Ksummit-2013-discuss] ARM topic: Is DT on ARM the solution, or is there something better?
Date: Fri, 25 Oct 2013 09:52:53 +0100 [thread overview]
Message-ID: <526A3165.4020601@wwwdotorg.org> (raw)
In-Reply-To: <1382614439.6040.16.camel@sakura.staff.proxad.net>
On 10/24/2013 12:33 PM, Maxime Bizon wrote:
>
> On Thu, 2013-10-24 at 10:52 +0100, Grant Likely wrote:
>
>> At this point if the hardware exists then it should be described in DTB,
>> even if it is merely compatible, reg, interrupts and maybe clocks
>
> if your driver does not use them, chances are you'll get them wrong.
>
>> properties. In many cases that is all that is required. It /is/ okay to
>> amend a binding later and to use default values if the new properties
>> aren't present.
>
> how do you handle the case of a wrong property, because you only wrote
> hardware description and not the driver ?
>
>> hardware description when enabling previously unused peripherals, but it
>> is absolutely not friendly to change a binding/driver in a what that fails on
>> previously working DTB (with the caveat that if no one notices, it
>> isn't breakage).
>
> ok then how do we solve that case:
>
> - Marvell SOC 1 is mainlined
> - Marvell SOC 2 is mainlined
> - Marvell SOC 'x' is mainlined
> - "PIO" hw crypto driver is written, working for all SOCs
> - [1 year]
> - SOCs bindings are marked as stable
> - [1 year]
> - someone rewrite the driver of hw crypto to use DMA, existing binding
> is not ok because clock 'foo' or interrupt 'bar', now required, are not
> present.
>
> what is the process merge that driver ?
>
> if the answer is that you need to keep PIO mode in driver so that
> existing DTBs still works with it, then this is just plain *wrong*.
That situation describes enabling a new feature. New features aren't
necessarily expected to work without revising the DT, e.g. adding new
properties/entries to describe the additional clocks/DMA-channels/...
that are required. In many cases, those additions can even be made in a
backwards-compatible way. Compatibility means that we shouldn't break
old functionality, not that we shouldn't augment the existing bindings.
next prev parent reply other threads:[~2013-10-25 8:52 UTC|newest]
Thread overview: 171+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-20 21:26 ARM topic: Is DT on ARM the solution, or is there something better? Stephen Warren
2013-10-20 22:08 ` [Ksummit-2013-discuss] " Mark Brown
2013-10-20 22:21 ` Stephen Warren
2013-10-21 1:00 ` Nicolas Pitre
2013-10-21 9:15 ` Thierry Reding
2013-10-21 14:57 ` Maxime Bizon
2013-10-21 17:07 ` Richard Cochran
2013-10-21 20:24 ` Stephen Warren
2013-10-22 9:24 ` Thierry Reding
2013-10-23 17:30 ` Richard Cochran
2013-10-23 19:06 ` Thierry Reding
2013-10-22 17:22 ` Jason Gunthorpe
2013-10-21 20:29 ` Stephen Warren
2013-10-21 20:40 ` Nicolas Pitre
2013-10-22 9:39 ` Thierry Reding
2013-10-22 15:04 ` Matt Porter
2013-10-22 17:13 ` Jason Gunthorpe
2013-10-22 17:49 ` Guenter Roeck
2013-10-23 8:06 ` Richard Cochran
2013-10-23 9:49 ` Thierry Reding
2013-10-23 17:16 ` Richard Cochran
2013-10-23 17:25 ` Matt Porter
2013-10-23 18:05 ` Richard Cochran
2013-10-23 18:57 ` Nicolas Pitre
2013-10-23 20:12 ` Matt Porter
2013-10-23 17:55 ` Nicolas Pitre
2013-10-23 18:13 ` Richard Cochran
2013-10-23 20:35 ` Thierry Reding
2013-10-23 17:29 ` Jason Gunthorpe
2013-10-23 17:45 ` Richard Cochran
2013-10-23 18:46 ` Maxime Bizon
2013-10-23 18:51 ` Richard Cochran
2013-10-23 19:12 ` Maxime Bizon
2013-10-24 9:52 ` Grant Likely
2013-10-24 11:33 ` Maxime Bizon
2013-10-24 11:47 ` David Woodhouse
2013-10-24 12:13 ` Maxime Bizon
2013-10-24 12:22 ` David Woodhouse
2013-10-24 12:22 ` David Woodhouse
2013-10-24 13:05 ` Maxime Bizon
2013-10-24 13:14 ` David Woodhouse
2013-10-24 13:46 ` Maxime Bizon
2013-10-24 19:52 ` Matt Porter
2013-10-24 20:11 ` Matt Sealey
2013-10-25 9:00 ` Stephen Warren
2013-10-24 12:23 ` Thierry Reding
2013-10-24 12:29 ` David Woodhouse
2013-10-24 13:00 ` Maxime Bizon
2013-10-24 13:10 ` David Woodhouse
2013-10-24 13:30 ` Maxime Bizon
2013-10-24 14:05 ` David Woodhouse
2013-10-24 14:19 ` Thierry Reding
2013-10-24 14:30 ` David Woodhouse
2013-10-24 14:38 ` Thierry Reding
2013-10-24 16:39 ` Nicolas Pitre
2013-10-24 16:45 ` David Woodhouse
2013-10-24 17:08 ` Nicolas Pitre
2013-10-24 18:15 ` jonsmirl at gmail.com
2013-10-24 14:32 ` Richard Cochran
2013-10-24 14:47 ` Thierry Reding
2013-10-24 15:37 ` Nicolas Pitre
2013-10-24 14:33 ` Maxime Bizon
2013-10-24 14:57 ` Thierry Reding
2013-10-24 16:27 ` Nicolas Pitre
2013-10-24 14:12 ` Thierry Reding
2013-10-24 14:22 ` David Woodhouse
2013-10-24 14:23 ` Thierry Reding
2013-10-24 14:38 ` David Woodhouse
2013-10-24 14:58 ` Thierry Reding
2013-10-24 19:58 ` Matt Porter
2013-10-24 23:54 ` Grant Likely
2013-10-25 8:52 ` Stephen Warren [this message]
2013-10-25 9:16 ` Thierry Reding
2013-10-23 17:47 ` Richard Cochran
2013-10-23 17:58 ` Nicolas Pitre
2013-10-23 18:02 ` Jason Gunthorpe
2013-10-23 18:23 ` Richard Cochran
2013-10-24 8:34 ` Thierry Reding
2013-10-24 15:00 ` Richard Cochran
2013-10-24 19:46 ` Matt Porter
2013-10-23 18:01 ` Guenter Roeck
2013-10-23 18:25 ` Jason Gunthorpe
2013-10-23 18:30 ` Richard Cochran
2013-10-23 18:54 ` Jason Gunthorpe
2013-10-24 8:06 ` Sascha Hauer
2013-10-24 8:17 ` Thierry Reding
2013-10-24 8:52 ` Sascha Hauer
2013-10-23 23:29 ` Ben Hutchings
2013-10-24 7:32 ` Richard Cochran
2013-10-24 9:35 ` Ben Hutchings
2013-10-24 12:02 ` Andre Heider
2013-10-24 8:01 ` Sascha Hauer
2013-10-24 8:11 ` Thierry Reding
2013-10-22 17:42 ` Nicolas Pitre
2013-10-22 18:21 ` Peter Maydell
2013-10-22 18:36 ` Nicolas Pitre
2013-10-22 19:16 ` Guenter Roeck
2013-10-22 20:12 ` Thierry Reding
2013-10-22 20:41 ` Nicolas Pitre
2013-10-22 21:39 ` Jason Gunthorpe
2013-10-23 8:50 ` Thierry Reding
2013-10-23 9:02 ` Thierry Reding
2013-10-22 20:42 ` Matt Porter
2013-10-23 10:04 ` Thierry Reding
2013-10-23 11:48 ` Peter Maydell
2013-10-23 16:29 ` Matt Porter
2013-10-22 6:47 ` David Brown
2013-10-20 23:11 ` Russell King - ARM Linux
2013-10-20 23:44 ` [Ksummit-2013-discuss] " Guenter Roeck
2013-10-20 23:51 ` Russell King - ARM Linux
2013-10-21 0:13 ` Guenter Roeck
2013-10-21 20:05 ` Stephen Warren
2013-10-22 9:45 ` Thierry Reding
2013-10-21 8:32 ` Sascha Hauer
2013-10-21 8:48 ` Russell King - ARM Linux
2013-10-21 9:27 ` Sascha Hauer
[not found] ` < CAF6AEGtt_2sStiZCNBp9btxevWghSwLZZBdN6ir8eUpX1FXrCQ@mail.gmail.com>
[not found] ` < 20131024072811.GS30088@pengutronix.de>
[not found] ` < CAF6AEGuEho9Ms7ifTE-EmBoQ-=_AXgvGcJxi5qEC0vsZ+H9C+A@mail.gmail.com>
2013-10-21 9:57 ` Russell King - ARM Linux
2013-10-21 10:24 ` Thierry Reding
2013-10-21 10:30 ` Russell King - ARM Linux
2013-10-21 10:41 ` Thierry Reding
2013-10-22 9:19 ` [Ksummit-2013-discuss] " Mark Brown
2013-10-21 20:09 ` Stephen Warren
2013-10-21 23:18 ` Sascha Hauer
2013-10-24 1:14 ` Rob Clark
2013-10-24 7:28 ` Sascha Hauer
2013-10-24 9:00 ` Thierry Reding
2013-10-24 9:21 ` Sascha Hauer
2013-10-24 21:21 ` Rob Clark
2013-10-25 9:24 ` Thierry Reding
2013-11-18 12:45 ` Russell King - ARM Linux
2013-11-18 15:37 ` Thierry Reding
2013-11-18 16:11 ` Russell King - ARM Linux
2013-11-18 16:18 ` Thierry Reding
2013-11-18 18:43 ` Mark Brown
2013-11-19 13:54 ` Grant Likely
2013-10-21 10:04 ` Thierry Reding
2013-10-21 10:57 ` [Ksummit-2013-discuss] " Laurent Pinchart
2013-10-21 10:00 ` Laurent Pinchart
2013-10-21 11:18 ` Sebastian Hesselbarth
2013-10-21 8:54 ` Thierry Reding
2013-10-21 20:19 ` Stephen Warren
2013-10-21 22:51 ` [Ksummit-2013-discuss] " Guenter Roeck
2013-10-22 10:27 ` James Hogan
2013-10-22 16:31 ` Jonathan Cameron
2013-10-22 16:49 ` Guenter Roeck
2013-10-22 20:35 ` Thierry Reding
2013-10-22 21:10 ` Guenter Roeck
2013-10-23 7:57 ` Thierry Reding
2013-10-23 16:01 ` Guenter Roeck
2013-10-23 21:07 ` Thierry Reding
2013-10-24 15:18 ` Guenter Roeck
2013-11-01 10:36 ` Thierry Reding
2013-11-01 13:30 ` Guenter Roeck
2013-10-22 20:48 ` Thierry Reding
2013-10-22 10:25 ` Thierry Reding
2013-10-22 21:44 ` Matt Sealey
2013-10-23 11:41 ` Peter Maydell
2013-10-23 23:02 ` [Ksummit-2013-discuss] " Rob Herring
2013-11-18 12:26 ` Thierry Reding
2013-11-18 13:40 ` Grant Likely
2013-11-18 13:57 ` Mark Brown
2013-11-18 15:29 ` Thierry Reding
2013-11-18 15:50 ` Mark Brown
2013-11-18 16:06 ` Thierry Reding
2013-11-18 17:16 ` Stephen Warren
2013-11-19 9:35 ` Thierry Reding
2013-11-19 17:27 ` Stephen Warren
2013-11-20 13:29 ` Thierry Reding
2013-11-18 18:35 ` Mark Brown
2013-11-19 9:11 ` Thierry Reding
2013-11-19 10:16 ` Mark Brown
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