HID: i2c-hid: Resolve touchpad issues on Dell systems during S4

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[ Upstream commit 7d62beb102 ]

Dell systems utilize an EC-based touchpad emulation when the ACPI
touchpad _DSM is not invoked. This emulation acts as a secondary
master on the I2C bus, designed for scenarios where the I2C touchpad
driver is absent, such as in BIOS menus. Typically, loading the
i2c-hid module triggers the _DSM at initialization, disabling the
EC-based emulation.

However, if the i2c-hid module is missing from the boot kernel
used for hibernation snapshot restoration, the _DSM remains
uncalled, resulting in dual masters on the I2C bus and
subsequent arbitration errors. This issue arises when i2c-hid
resides in the rootfs instead of the kernel or initramfs.

To address this, switch from using the SYSTEM_SLEEP_PM_OPS()
macro to dedicated callbacks, introducing a specific
callback for restoring the S4 image. This callback ensures
the _DSM is invoked.

Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Mario Limonciello (AMD) 2025-09-09 06:00:06 -05:00 • committed by Greg Kroah-Hartman

parent 689ca6be7e

commit 262e830ce1

3 changed files with 37 additions and 1 deletions

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8

drivers/hid/i2c-hid/i2c-hid-acpi.c

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28

drivers/hid/i2c-hid/i2c-hid-core.c

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2

drivers/hid/i2c-hid/i2c-hid.h

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