Re: [PATCH] Input: synaptics - add LEN2058 to SMBus passlist for ThinkPad E490

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The commit message incorrectly states that without the passlist entry, psmouse ignores the `synaptics_intertouch` parameter and falls back to PS/2 mode even when explicitly requested.
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commit 18925dd22ddb975fc9e545765ec54eb77a26f6f6
Author: Nicolás Bazaes <contacto@bazaes.cl>

Input: synaptics - add LEN2058 to SMBus passlist for ThinkPad E490

The Lenovo ThinkPad E490 has a Synaptics TM3471-020 touchpad that supports
SMBus/RMI4 mode but is not listed in smbus_pnp_ids[]. Adding LEN2058 to
the passlist enables RMI4 over SMBus, which provides better multitouch
support and matches the behavior of similar ThinkPad models.

> Without this entry, psmouse ignores the
> synaptics_intertouch parameter and falls back to PS/2 mode even when
> explicitly requested.

This isn't a bug, but is this description accurate?

Looking at synaptics_setup_intertouch(), the passlist is only checked if
synaptics_intertouch == SYNAPTICS_INTERTOUCH_NOT_SET:

drivers/input/mouse/synaptics.c:synaptics_setup_intertouch() {
    ...
	if (synaptics_intertouch == SYNAPTICS_INTERTOUCH_NOT_SET) {
		if (!psmouse_matches_pnp_id(psmouse, topbuttonpad_pnp_ids) &&
		    !psmouse_matches_pnp_id(psmouse, smbus_pnp_ids)) {
    ...
}

If a user explicitly requests SMBus mode by passing
psmouse.synaptics_intertouch=1, the condition is false, bypassing the
passlist check entirely and honoring the user's request.

Could the commit message be updated to clarify that the parameter is not
ignored when explicitly requested?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260513045749.185969-1-contacto@bazaes.cl?part=1