Messages in this thread | | | Date | Fri, 11 Apr 2014 10:20:28 +0100 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] of/platform: Fix no irq domain found errors when populating interrupts |
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On Thu, Apr 10, 2014 at 02:38:09PM -0700, Tony Lindgren wrote: > Currently we get the following kind of errors if we try to use interrupt > phandles to irqchips that have not yet initialized: > > irq: no irq domain found for /ocp/pinmux@48002030 ! > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 1 at drivers/of/platform.c:171 of_device_alloc+0x144/0x184() > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-00038-g42a9708 #1012 > (show_stack+0x14/0x1c) > (dump_stack+0x6c/0xa0) > (warn_slowpath_common+0x64/0x84) > (warn_slowpath_null+0x1c/0x24) > (of_device_alloc+0x144/0x184) > (of_platform_device_create_pdata+0x44/0x9c) > (of_platform_bus_create+0xd0/0x170) > (of_platform_bus_create+0x12c/0x170) > (of_platform_populate+0x60/0x98) > > This is because we're wrongly trying to populate resources that are not yet > available. It's perfectly valid to create irqchips dynamically, so let's > fix up the issue by populating the interrupt resources at the driver probe > time instead. > > Note that at least currently we cannot dynamically allocate the resources as bus > specific code may add legacy resources with platform_device_add_resources() > before the driver probe. At least omap_device_alloc() currently relies on > num_resources to determine if legacy resources should be added. Some of these > will clear automatically when mach-omap2 boots with DT only, but there are > probably other places too where platform_device_add_resources() modifies > things before driver probe. > > This patch was discussed quite a bit earlier, but so far it seems we don't > have any better options to fix the problem. For the earlier discussion, > please see: > > https://lkml.org/lkml/2013/11/22/520 > > The addition of of_platform_probe() is based on patches posted earlier by > Thierry Reding <thierry.reding@gmail.com>. > > Signed-off-by: Tony Lindgren <tony@atomide.com>
So what happens if a device driver probe function:
- creates a new platform device - copies the resources from the original to the new device - copies the of_node from the original to the new device - registers the new device
Yes, it's broken (because it can result in the same driver being re-probed by the new device) but we *do* have stuff in the kernel tree which does this.
-- FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly improving, and getting towards what was expected from it.
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