On 3.03.2023 10:53, Krzysztof Kozlowski wrote:
On 03/03/2023 08:44, Arınç ÜNAL wrote:
On 3.03.2023 10:05, Krzysztof Kozlowski wrote:
On 02/03/2023 12:50, Arınç ÜNAL wrote:
On 2.03.2023 14:36, Krzysztof Kozlowski wrote:
On 02/03/2023 11:47, Arınç ÜNAL wrote:
On 2.03.2023 13:29, Krzysztof Kozlowski wrote:
On 02/03/2023 11:22, Arınç ÜNAL wrote:
## Incorrect naming
MT7620, MT7621, MT7628, and MT7688 SoCs are incorrectly called Ralink,
introduce new ralink->mediatek compatible strings to address it.
So this part was addressed by Rob - we don't do it, because it does not
matter. Ralink is now Mediatek, thus there is no conflict and no issues
with different vendor used.
I think Rob was rather addressing that updating compatible strings based
on acquisition or marketing whims is not permitted. This condition does
not apply here as these SoCs were never Ralink.
I understand your point that Ralink is now MediaTek but still, calling
these SoCs Ralink would be a bit misleading, don't you think?
Misleading yes, but also does not matter. At least matter not enough to
justify ABI break, so you would need to deprecate old ones and keep
everything backwards compatible. You still would affect 3rd party users
of DTS, though...
I intend to do just that. Introduce new mediatek strings, keep the old
ones so it's backwards compatible, therefore don't break the ABI.
Instead of deprecating old strings, I intend to introduce the checks I
mentioned, on the schema, so the pin muxing bindings only apply if the
DT has got a string that won't match multiple schemas. This way it
shouldn't affect 3rd party DTs.
I meant, 3rd party users of DTS. You will replace the compatible in the
DTS, right? So the DTS exported and used in all other projects, OS,
firmwares, bootloaders, out of tree kernel forks will stop working.
I plan to change it on the DTs for MediaTek SoCs, yes. Is this a
problem? From what I can tell, what must be ensured is that old DTs must
work with newer kernels, not new DTs on older kernels.
Can I be clearer than this?
" So the DTS exported and used in all other projects, OS,
firmwares, bootloaders, out of tree kernel forks will stop working."
Yes, this is a problem - they will stop working.
I've never seen any project just exporting DTs from the latest kernel
version and slap it onto old versions, as a new devicetree that was
Really? U-Boot does it all the time, other projects (like BSD) do it
periodically to some extend as well.
They must do heavy reviewing before shipping it. Drivers like MediaTek
ethernet on U-Boot is different than in Linux, the dt-bindings are all
different. Under a review, these changes will pop out for them to
address so there're no problems.
introduced with a newer kernel version is not guaranteed to work with
older kernel versions.
Not guaranteed but it is expected, though, to some level and under some
conditions. Therefore it might be or might not be a problem. For some
platforms no one cares. For some people care.
I'm going to assume there's not much care for this platform, at least
for mt7621, as I've heard no complaints when I did this before.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/mips/boot/dts/ralink/mt7621.dtsi?id=b4f209e32ba5c283e7b1dd00d867b0536d3e215e
If someone is actually doing this on a project, I think it's the
responsibility of the maintainers of these said projects to account for
this and modify the DT for the kernel version they're running it on.
What's more usual is one'd run the kernel version where the new DT was
introduced, which will work fine.
"kernel" as Linux is only one part of it. I mentioned several other
projects.
On to real life implications, popular projects like U-Boot and OpenWrt
maintain their own DTs for this platform so I think the impact is very
minimal.
And they sync with Linux kernel DTS.
Again, the DTs must be reviewed so they will be modified and the
potential issue will be addressed.
Arınç
