[PATCH] HID: i2c-hid: Resolve touchpad issues on Dell systems during S4
flat view
STALE386d
From: "Mario Limonciello (AMD)" <superm1@kernel.org>
Date: 2025-09-09 11:00:19
Subsystem:
hid core layer, the rest · Maintainers:
Jiri Kosina, Benjamin Tissoires, Linus Torvalds
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> --- drivers/hid/i2c-hid/i2c-hid-acpi.c | 8 ++++++++ drivers/hid/i2c-hid/i2c-hid-core.c | 28 +++++++++++++++++++++++++++- drivers/hid/i2c-hid/i2c-hid.h | 2 ++ 3 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/i2c-hid/i2c-hid-acpi.c b/drivers/hid/i2c-hid/i2c-hid-acpi.c
index 1b49243adb16a..abd700a101f46 100644
--- a/drivers/hid/i2c-hid/i2c-hid-acpi.c
+++ b/drivers/hid/i2c-hid/i2c-hid-acpi.c@@ -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)
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index d3912e3f2f13a..3257aa87be898 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c@@ -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);
diff --git a/drivers/hid/i2c-hid/i2c-hid.h b/drivers/hid/i2c-hid/i2c-hid.h
index 2c7b66d5caa0f..1724a435c783a 100644
--- a/drivers/hid/i2c-hid/i2c-hid.h
+++ b/drivers/hid/i2c-hid/i2c-hid.h@@ -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,
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2.43.0