Re: [PATCH v3 4/4] leds: flash: lm3643: Describe the LED on the Lenovo ThinkPad X9-15 Gen 1

[Ruslan Koreev]

Hi Lee,

We can share the board-description code in ipu-bridge and add flash-leds,
as Sakari and Andy suggested, while keeping per-board current settings.

Lenovo's packages set IRFlashLedIntensity=30 for the X1 [1] and 40 for
the X9 [2]. With both outputs using the same current setting, these
convert to nominal totals of 467350 uA and 608050 uA respectively. The
X9 result matches Rillian's trace; the X1 result is from static analysis,
with live Windows behavior still unverified.

My earlier claim that Windows applies a fixed configuration to any
LM3643 was too broad: the sensor configuration affects the current request.

Both default paths configure a 400 ms controller timeout. Actual mode,
pulse duration and continuous-torch limits remain unverified, so these
are candidate operating settings rather than established LED limits.

Rillian, could you share the relevant SPB trace, including mode, current
and timeout writes, together with the installed driver version?

[1] https://download.lenovo.com/pccbbs/mobiles/n4oce17w.html
[2] https://download.lenovo.com/pccbbs/mobiles/n4cim20w.html

Ruslan