[Skiboot] [PATCH] console(lpc/fsp-console): Use just stdout-path.

[Oliver]

On Fri, Mar 2, 2018 at 4:10 AM, ppaidipe <ppaidipe at linux.vnet.ibm.com> wrote:
> On 2018-03-01 12:36, Stewart Smith wrote:
>>
>> Pridhiviraj Paidipeddi <ppaidipe at linux.vnet.ibm.com> writes:
>>>
>>> dtc tool complaining about below warning as usage of linux,stdout-path
>>> property under /chosen node is deprecated.

Hmm, dtc is largely intended for the embedded community who have the
ability to fix up the DTB to better match what a specific kernel
versions expects while we don't have that luxury. We need to ensure
old kernels will continue to boot with a newer skiboot so we're forced
to keep the "deprecated" parts of the DT around. IMO the warning is
kind of bogus for our situation so we might want to look at adding a
switch to dtc so that it complains less about this sort of issue.

>>>
>>> dts: Warning
>>> (chosen_node_stdout_path): Use 'stdout-path' instead of
>>> 'linux,stdout-path'
>>>
>>> So this patch will fix this by using just stdout-path property for
>>> specifying
>>> to the node which represents the device to be used for boot console
>>> output.
>>>
>>> Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe at linux.vnet.ibm.com>
>>> ---
>>>  core/console.c       | 4 ++--
>>>  core/init.c          | 2 +-
>>>  hw/fsp/fsp-console.c | 6 +++---
>>>  hw/lpc-uart.c        | 4 ++--
>>>  4 files changed, 8 insertions(+), 8 deletions(-)
>>
>>
>> As kind of discussed on internal slack, the kernel commit that will pick
>> up the 'stdout-path' property is this one:
>>
>> commit 676e1b2fcd9dbb47a59baac13d089621d22c68b8
>> Author: Grant Likely <grant.likely at linaro.org>
>> Date:   Thu Mar 27 17:11:23 2014 -0700
>>
>>     of: Add support for ePAPR "stdout-path" property
>>
>>     ePAPR 1.1 defines the "stdout-path" property for specifying the
>> console
>>     device, but Linux currently only handles the older "linux,stdout-path"
>>     property. This patch adds parsing for the new property name.
>>
>>     Signed-off-by: Grant Likely <grant.likely at linaro.org>
>>
>> which came in in v3.14-rc5-29-g676e1b2fcd9d - which is after when it's
>> generally accepted that things should work on p8.
>>
>> So, if we do this with a "if power9" (as in, p9 cpu or greater) then we
>> should be okay.
>>
>> I'm not sure what the effect is of putting both in on p8? That may be
>> okay too (I'm not sure what the test looks for).
>
>
> Thanks for that info. Yes, On P8 adding both properties passed old and new
> kernel
> booting as well as dtc tests. And from P9 and above we will just add
> stdout-path
> property. Fixed the necessary checks and sent V2.
> https://lists.ozlabs.org/pipermail/skiboot/2018-March/010623.html
>
> Thanks
> Pridhiviraj
>
>
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