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From: arnd@arndb•de (Arnd Bergmann)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 02/16] drivers/gpio: gpio-nomadik: Add support for irqdomains
Date: Thu, 19 Apr 2012 16:23:06 +0000	[thread overview]
Message-ID: <201204191623.07445.arnd@arndb.de> (raw)
In-Reply-To: <CACRpkdaTFatBK4GyzCzm=U6+h8Knnf6xY9X6Uc26sLxQb2OhtA@mail.gmail.com>

On Wednesday 18 April 2012, Linus Walleij wrote:
> 
> On Wed, Apr 18, 2012 at 6:22 PM, Arnd Bergmann <arnd@arndb•de> wrote:
> 
> > The problem is that we cannot put the interrupt resources into the platform
> > device until the irq domain has been added. Right now, we set the gic
> > interrupt domain from init_IRQ(), then add the load the gpio
> > driver from core_initcall(nmk_gpio_init) and add the platform devices
> > from arch_initcall(customize_machine).
> >
> > This feels fragile because it depends on the gpio device getting probed
> > before any device using the gpio interrupts. It does seem to work fine
> > right now, but I'm not convinced that this is just coincidence.
> 
> Aha OK. Why not put in that big comment then, thus nobody will
> ever miss the point like I did :-)
> 

I think I've just come up with a solution to this problem and would
like to hear what Rob and Grant think about this:

If we move the code that adds the resources to a platform_device
from of_device_alloc() to  platform_drv_probe(), we can defer
looking up the interrupt number until the driver actually gets
probed and bail out early with -EPROBE_DEFER if the irq domain
is not available yet. That will even work when we have a builtin
driver for a device that uses a GPIO interrupt and the gpio controller
driver is a loadable module.

	Arnd

  reply	other threads:[~2012-04-19 16:23 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-17 10:43 [PATCH 0/16] Another round of Device Tree enablement for Snowball Lee Jones
2012-04-17 10:43 ` [PATCH 01/16] ARM: ux500: Enable the external bus with Device Tree Lee Jones
2012-04-18 15:54   ` Linus Walleij
2012-04-17 10:43 ` [PATCH 02/16] drivers/gpio: gpio-nomadik: Add support for irqdomains Lee Jones
2012-04-18 16:09   ` Linus Walleij
2012-04-18 16:22     ` Arnd Bergmann
2012-04-18 16:26       ` Linus Walleij
2012-04-19 16:23         ` Arnd Bergmann [this message]
2012-04-20  3:01           ` Rob Herring
2012-05-17 21:49             ` Grant Likely
2012-04-20  6:47           ` Linus Walleij
2012-04-17 10:43 ` [PATCH 03/16] ARM: ux500: Use correct format for dynamic IRQ assignment Lee Jones
2012-04-18 16:11   ` Linus Walleij
2012-04-17 10:43 ` [PATCH 04/16] drivers/net: Do not free an IRQ if its request failed Lee Jones
2012-04-18 16:12   ` Linus Walleij
2012-04-17 10:43 ` [PATCH 05/16] ARM: ux500: New DT:ed snowball_platform_devs for one-by-one device enablement Lee Jones
2012-04-17 10:43 ` [PATCH 06/16] ARM: ux500: New DT:ed u8500_init_devices " Lee Jones
2012-04-17 10:43 ` [PATCH 07/16] ARM: ux500: Enable the SMSC9115 on Snowball via Device Tree Lee Jones
2012-04-18 16:16   ` Linus Walleij
2012-04-17 10:44 ` [PATCH 08/16] drivers/mmc: MMCI: Use correct GPIO binding for IRQ requests Lee Jones
2012-04-18 16:18   ` Linus Walleij
2012-04-17 10:44 ` [PATCH 09/16] ARM: ux500: Correctly describe SMSC9115 for Snowball in DT Lee Jones
2012-04-17 10:44 ` [PATCH 10/16] drivers/gpio: represent gpio-nomadik as an IRQ controller in DT documentation Lee Jones
2012-04-17 14:38   ` Arnd Bergmann
2012-04-17 15:32     ` Lee Jones
2012-04-17 15:45     ` [PATCH 10/16 v2] " Lee Jones
2012-04-17 15:58     ` Lee Jones
2012-04-17 10:44 ` [PATCH 11/16] ARM: ux500: Do not attempt to register non-existent i2c devices on Snowball Lee Jones
2012-04-17 14:42   ` Arnd Bergmann
2012-04-17 15:28     ` Lee Jones
2012-04-17 15:44   ` [PATCH 11/16 v2] " Lee Jones
2012-04-17 16:02     ` Arnd Bergmann
2012-04-17 10:44 ` [PATCH 12/16] mfd/db8500-prcmu: Register as a platform driver instead of only probing Lee Jones
2012-04-18 16:19   ` Linus Walleij
2012-04-17 10:44 ` [PATCH 13/16] mfd/db8500-prcmu: Add Device Tree support Lee Jones
2012-04-18 16:35   ` Linus Walleij
2012-04-17 10:44 ` [PATCH 14/16] ARM: ux500: Fork cpu-db8500 platform_devs for sequential DT enablement Lee Jones
2012-04-17 10:44 ` [PATCH 15/16] ARM: ux500: Apply Device Tree settings for the DB8500 PRCMU Lee Jones
2012-04-17 14:47   ` Arnd Bergmann
2012-04-17 15:30     ` Lee Jones
2012-04-17 15:38       ` Arnd Bergmann
2012-04-17 15:46         ` Lee Jones
2012-04-17 15:56   ` [PATCH 13&15/16 v2] " Lee Jones
2012-04-18 16:21     ` Linus Walleij
2012-04-17 10:44 ` [PATCH 16/16] ARM: ux500: Enable PRCMU Timer 4 (clocksource) via Device Tree Lee Jones
2012-04-17 14:49 ` [PATCH 0/16] Another round of Device Tree enablement for Snowball Arnd Bergmann

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