Commit 7d62beb1 authored by Mario Limonciello (AMD)'s avatar Mario Limonciello (AMD) Committed by Benjamin Tissoires
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HID: i2c-hid: Resolve touchpad issues on Dell systems during S4 



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: default avatarMario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
parent 02d6eeed

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

+8 −0
Original line number Diff line number Diff line
@@ -76,6 +76,13 @@ static int i2c_hid_acpi_get_descriptor(struct i2c_hid_acpi *ihid_acpi) 
	return hid_descriptor_address;

}



static void i2c_hid_acpi_restore_sequence(struct i2chid_ops *ops)

{

	struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);



	i2c_hid_acpi_get_descriptor(ihid_acpi);

}



static void i2c_hid_acpi_shutdown_tail(struct i2chid_ops *ops)

{

	struct i2c_hid_acpi *ihid_acpi = container_of(ops, struct i2c_hid_acpi, ops);
@@ -96,6 +103,7 @@ static int i2c_hid_acpi_probe(struct i2c_client *client) 


	ihid_acpi->adev = ACPI_COMPANION(dev);

	ihid_acpi->ops.shutdown_tail = i2c_hid_acpi_shutdown_tail;

	ihid_acpi->ops.restore_sequence = i2c_hid_acpi_restore_sequence;



	ret = i2c_hid_acpi_get_descriptor(ihid_acpi);

	if (ret < 0)

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

+27 −1
Original line number Diff line number Diff line
@@ -961,6 +961,14 @@ static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid) 
	ihid->ops->shutdown_tail(ihid->ops);

}



static void i2c_hid_core_restore_sequence(struct i2c_hid *ihid)

{

	if (!ihid->ops->restore_sequence)

		return;



	ihid->ops->restore_sequence(ihid->ops);

}



static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)

{

	struct i2c_client *client = ihid->client;
@@ -1360,8 +1368,26 @@ static int i2c_hid_core_pm_resume(struct device *dev) 
	return i2c_hid_core_resume(ihid);

}



static int i2c_hid_core_pm_restore(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct i2c_hid *ihid = i2c_get_clientdata(client);



	if (ihid->is_panel_follower)

		return 0;



	i2c_hid_core_restore_sequence(ihid);



	return i2c_hid_core_resume(ihid);

}



const struct dev_pm_ops i2c_hid_core_pm = {

	SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)

	.suspend = pm_sleep_ptr(i2c_hid_core_pm_suspend),

	.resume = pm_sleep_ptr(i2c_hid_core_pm_resume),

	.freeze = pm_sleep_ptr(i2c_hid_core_pm_suspend),

	.thaw = pm_sleep_ptr(i2c_hid_core_pm_resume),

	.poweroff = pm_sleep_ptr(i2c_hid_core_pm_suspend),

	.restore = pm_sleep_ptr(i2c_hid_core_pm_restore),

};

EXPORT_SYMBOL_GPL(i2c_hid_core_pm);

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

+2 −0
Original line number Diff line number Diff line
@@ -27,11 +27,13 @@ static inline u32 i2c_hid_get_dmi_quirks(const u16 vendor, const u16 product) 
 * @power_up: do sequencing to power up the device.

 * @power_down: do sequencing to power down the device.

 * @shutdown_tail: called at the end of shutdown.

 * @restore_sequence: hibernation restore sequence.

 */

struct i2chid_ops {

	int (*power_up)(struct i2chid_ops *ops);

	void (*power_down)(struct i2chid_ops *ops);

	void (*shutdown_tail)(struct i2chid_ops *ops);

	void (*restore_sequence)(struct i2chid_ops *ops);

};



int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,