Re: [PATCH RFC 0/2] Novatek NT51021 DSI panel IC driver

[Nickolay Goppen <setotau@mainlining.org>]

07.09.2026 09:01, Ryan Brue wrote:
> Hi Nickolay,
>
> I sent a duplicate NT51021 driver on September 5th without finding
> yours from the 29th first. That was my mistake, and I have withdrawn
> mine. That's my bad, I'm new to kernel development :)
>
> Since I had the hardware set up, I tested your series on the device I
> am working on: the Amazon Fire HD 10 (2017), an MT8173 tablet with a BOE
> 1200x1920 NT51021 module, driven by mediatek-drm rather than msm. It
> works.
>
> Concretely, on that panel:
>
>    - your 10.1" register sequence, timings and mode_flags, unmodified,
>      bring the panel up correctly at your 60 Hz / 993.5 Mbps per lane
>    - it also works with my vendor's own sequence and timings under your
>      driver, at 62.5 Hz / 980 Mbps
>    - verified across a cold boot, display off and on cycles and a
>      suspend/resume, with the MIPI TX PLL reading back at the intended
>      rate each time
>
> So, for what it is worth on hardware you cannot test:
>
> Tested-by: Ryan Brue <ryanbrue.dev@gmail.com>
>
> Two things I checked that might save you answering them later:
>
>    - The generic writes are right. Xiaomi's own panel dtsi uses dtype
>      0x29, and this panel accepts both generic and DCS short writes, so
>      nothing depends on the choice.
>
>    - prepare() never sending a set_display_on looked like an omission to
>      me at first, but the 0x01 software reset at the head of the init
>      restores it, and repeated off and on cycles pass. It may be worth a
>      comment, since unprepare() does send set_display_off and the
>      asymmetry invites the question.
>
> One question on the binding, which is as much about my patch as yours.
> Where does "boe,tv101wum-nx0" come from? Xiaomi's panel dtsi
> (dsi-panel-nt51021-boe-10wu-video.dtsi) gives only
>
>      qcom,mdss-dsi-panel-name = "NT51021_BOE_BOE10";
>
> with no part number, and the register sequence in your driver matches
> that file byte for byte. TV101WUM-NX0 is a real BOE part, and its
> datasheet active area of 216.576 x 135.36 mm agrees nicely with the
> 135 x 216 in that dtsi, so the attribution looks reasonable. But if it
> is inferred rather than read off the panel or a BOM, it may be worth
> saying so in the commit message, or naming the compatible after the
> board the way panel-novatek-nt36523.c does for
> xiaomi,elish-boe-nt36523.
>
> I ask because my module has no identity I can establish at all. It
> answers no DSI read, DCS or generic, before or after sleep-out; the
> vendor kernel and bootloader name it only "BOE", chosen from two board
> ID straps; and its vendor-declared physical height is arithmetically
> impossible, since 1200/136 and 1920/221 disagree by 1.5%. So I am
> naming mine after the board, and would rather not accidentally imply it
> is or is not your part.

I've found these part numbers on the photos of a replacement panels from 
the AliExpress.

Also, for TV101WUM-NX0, I have a confirmation from Alexey Min, who 
disassembled
Xiaomi Mi Pad 4 Plus and took a photo of the panel's part number.

> If it is useful, I have the Fire HD 10 panel ready as a variant on top
> of your series: two patches, binding and driver, adding
> amazon,suez-boe-nt51021. The only change it needs in your code is
> making mode_flags per variant. My vendor asks for sync-event video mode
> with a continuously running HS clock rather than burst, and your two
> panels keep exactly the flags they have now. Burst worked on my panel
> too, so this is about matching what the module is characterised for,
> not a fix.
I will try to do that. Can I add you to the maintainers of this panel 
driver?
> I will hold that until your v2, since Neil's renaming will touch every
> identifier it adds. Happy to test v2 on this hardware when you post it.
>
> Thanks for doing this first.
>
> Ryan

-- 
Best regards,
Nickolay