[linux-nvidia-6.17] NVIDIA: SAUCE: mediatek 8250 UART change

[abhsahu]

We have applied SAUCE patch for adding serial port support for GB10.
Mediatek has sent the changes in mailing list https://patchwork.kernel.org/project/linux-mediatek/patch/20260105024103.2027085-2-zhiyong.tao@mediatek.com/ which is under review.

This PR reverts the previous SAUCE patch and applies the latest version from the mailing list.
The only functional difference is the addition of the NVDA0240 ACPI ID apart from MTKI0511.

[nirmoy]

@abhsahu Do we need this NVDA0240 change ? I would wait till the mailing list patch is merged if the NVDA0240 change is not needed.

[nvmochs]

@abhsahu

I have no issues with the backport but do have a couple of comments...

• Would it make sense to wait until this is accepted upstream? As it is now we are replacing a SAUCE patch with a SAUCE patch and there is little functional difference? Do we need "NVDA0240" at this time?
• In the revert patch, please include a brief comment explaining why this is being reverted (i.e. it is being replaced by the upstream candidate).
• Instead of "This patch is applied from https://patchwork.kernel.org/project/linux-mediatek/patch/20260105024103.2027085-2-zhiyong.tao@mediatek.com/", please add a "backported from" tag after the original patch signoffs but before your signoff.

e.g.

NVIDIA: SAUCE: MEDIATEK: serial: 8250_mtk: Add ACPI support

Add ACPI support to 8250_mtk driver. This makes it possible to
use UART on ARM-based desktops with EDK2 UEFI firmware.
    
Signed-off-by: Yenchia Chen <yenchia.chen@mediatek.com>
Signed-off-by: Zhiyong.Tao <zhiyong.tao@mediatek.com>
(backported from https://lore.kernel.org/all/20260105024103.2027085-2-zhiyong.tao@mediatek.com/)
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>

[abhsahu]

Thanks @nirmoy and @nvmochs for your feedback.
I am following up with Mediatek internally to see if we can get this change accepted.

We don't have NVDA0240 for the existing DGX Spark BSP, but this may be needed in the future if we plan to change the BSP codebase branch.
We are using NVDA0240 in the latest internal code for the main branch. This is needed to boot the same BaseOS image with those BSPs.

[nirmoy]

@abhsahu I see if we need NVDA0240 ref in the future then let's work on getting this merge. Please update the PR with Matt's comment and also don't forget to add your signoff for the revert patch.