Re: [PATCH 2/2] of: use platform_device_add

From: Fabio Estevam
Date: Sun Feb 17 2013 - 08:18:46 EST


On Sun, Feb 17, 2013 at 4:43 AM, Shawn Guo <shawn.guo@xxxxxxxxxx> wrote:
> On Sun, Feb 17, 2013 at 11:03:35AM +0800, Shawn Guo wrote:
>> On Fri, Jan 18, 2013 at 01:40:00AM +0000, Grant Likely wrote:
>> > This allows platform_device_add a chance to call insert_resource on all
>> > of the resources from OF. At a minimum this fills in proc/iomem and
>> > presumably makes resource tracking and conflict detection work better.
>> > However, it has the side effect of moving all OF generated platform
>> > devices from /sys/devices to /sys/devices/platform/. It /shouldn't/
>> > break userspace because userspace is not supposed to depend on the full
>> > path (because userspace always does what it is supposed to, right?).
>> >
>> > This may cause breakage if either:
>> > 1) any two nodes in a given device tree have overlapping & staggered
>> > regions (ie. 0x80..0xbf and 0xa0..0xdf; where one is not contained
>> > within the other). In this case one of the devices will fail to
>> > register and an exception will be needed in platform_device_add() to
>> > complain but not fail.
>>
>> Grant,
>>
>> The patch introduce a regression on imx6q boot.
>
> It also breaks all of_amba_device users.
>
> of_amba_device_create() --> amba_device_add() --> request_resource()
> and fails.

Yes, correct: amba-pl011 does not register anymore after this patch,
which causes the serial console to be not functional.
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