[U-Boot] [PATCH] tegra: trimslice: fix a couple typos

Igor Grinberg grinberg at compulab.co.il
Fri Jun 1 08:38:17 CEST 2012


On 05/31/12 19:50, Stephen Warren wrote:
> On 05/31/2012 04:13 AM, Marek Vasut wrote:
>> Dear Igor Grinberg,
>>
>>> On 05/30/12 19:45, Stephen Warren wrote:
>>>> From: Stephen Warren <swarren at nvidia.com>
>>>>
>>>> Fix the .dts file USB unit addresses not to duplicate each-other.
>>>>
>>>> Fix the board name string to indicate the vendor is Compulab not NVIDIA.
>>>>
>>>> Signed-off-by: Stephen Warren <swarren at nvidia.com>
>>>
>>> Acked-by: Igor Grinberg <grinberg at compulab.co.il>
>>
>> Do we have one copy of the dts files here and one in Linux kernel tree? Are they 
>> the same?
> 
> Both U-Boot and the kernel have their own copies of the .dts files.
> 
> In general, the U-Boot copy would be identical to what's in the kernel,
> or a pure subset since mostly the kernel's driver support is more
> advanced, so we've added more nodes to the DT.
> 
> That said, there are unfortunately some bizarre quirks in the way the
> U-Boot parses the device tree, such as requiring the /aliases node in
> order to enumerate at least some devices, the use of the Tegra clock
> binding that hasn't been incorporated into the kernel yet and is used
> for both clock and module reset functionality even though it's really
> only intended for clock functionality, and various other small
> properties that are U-Boot specific (although I forget if we managed to
> eliminate these all or not). These all end up causing differences
> between the two device tree files:-(

Thanks for the information.

I don't see any problem with having differences between the .dts files
in kernel and U-Boot, because the way I see it:
The .dts file we have in kernel should provide a way for a DT aware kernel
to boot on even non-DT aware U-Boot (as the DT blob can be appended
to the kernel binary).
The .dts file in U-Boot can have a basic settings and the binary DT blob
can be updated by U-Boot at run time, just before loading kernel.

Also, IIRC, the intension was to remove the kernel .dts files after
"all bootloaders" know to boot the DT kernel...

-- 
Regards,
Igor.


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