On Tue, Mar 02, 2021 at 03:50:57PM +0100, Hans de Goede wrote: > Several users have been reporting that elants_i2c gives several errors > during probe and that their touchscreen does not work on their Lenovo AMD > based laptops with a touchscreen with a ELAN0001 ACPI hardware-id: > > [ 0.550596] elants_i2c i2c-ELAN0001:00: i2c-ELAN0001:00 supply vcc33 not found, using dummy regulator > [ 0.551836] elants_i2c i2c-ELAN0001:00: i2c-ELAN0001:00 supply vccio not found, using dummy regulator > [ 0.560932] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (77 77 77 77): -121 > [ 0.562427] elants_i2c i2c-ELAN0001:00: software reset failed: -121 > [ 0.595925] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (77 77 77 77): -121 > [ 0.597974] elants_i2c i2c-ELAN0001:00: software reset failed: -121 > [ 0.621893] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (77 77 77 77): -121 > [ 0.622504] elants_i2c i2c-ELAN0001:00: software reset failed: -121 > [ 0.632650] elants_i2c i2c-ELAN0001:00: elants_i2c_send failed (4d 61 69 6e): -121 > [ 0.634256] elants_i2c i2c-ELAN0001:00: boot failed: -121 > [ 0.699212] elants_i2c i2c-ELAN0001:00: invalid 'hello' packet: 00 00 ff ff > [ 1.630506] elants_i2c i2c-ELAN0001:00: Failed to read fw id: -121 > [ 1.645508] elants_i2c i2c-ELAN0001:00: unknown packet 00 00 ff ff > > Despite these errors, the elants_i2c driver stays bound to the device > (it returns 0 from its probe method despite the errors), blocking the > i2c-hid driver from binding. > > Manually unbinding the elants_i2c driver and binding the i2c-hid driver > makes the touchscreen work. > > Check if the ACPI-fwnode for the touchscreen contains one of the i2c-hid > compatiblity-id strings and if it has the I2C-HID spec's DSM to get the > HID descriptor address, If it has both then make elants_i2c not bind, > so that the i2c-hid driver can bind. > > This assumes that non of the (older) elan touchscreens which actually > need the elants_i2c driver falsely advertise an i2c-hid compatiblity-id > + DSM in their ACPI-fwnodes. If some of them actually do have this > false advertising, then this change may lead to regressions. > > Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207759 > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > drivers/input/touchscreen/elants_i2c.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c > index 4c2b579f6c8b..510638e5ba5a 100644 > --- a/drivers/input/touchscreen/elants_i2c.c > +++ b/drivers/input/touchscreen/elants_i2c.c > @@ -1334,6 +1334,12 @@ static void elants_i2c_power_off(void *_data) > } > } > > +static const struct acpi_device_id i2c_hid_ids[] = { > + {"ACPI0C50", 0 }, > + {"PNP0C50", 0 }, > + { }, > +}; This ideally needs to be protected by CONFIG_ACPI. > + > static int elants_i2c_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -1342,6 +1348,25 @@ static int elants_i2c_probe(struct i2c_client *client, > unsigned long irqflags; > int error; > > +#ifdef CONFIG_ACPI > + /* Don't bind to i2c-hid compatible devices, these are handled by the i2c-hid drv. */ > + if (acpi_match_device_ids(ACPI_COMPANION(&client->dev), i2c_hid_ids) == 0) { > + static const guid_t i2c_hid_guid = > + GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555, > + 0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE); > + acpi_handle handle = ACPI_HANDLE(&client->dev); > + union acpi_object *obj; > + > + obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, > + ACPI_TYPE_INTEGER); > + if (obj) { > + dev_warn(&client->dev, "elants_i2c: This device appears to be an I2C-HID device, not binding\n"); No need for "elants_i2c" prefix as dev_warn already gives driver info I believe. > + ACPI_FREE(obj); > + return -ENODEV; > + } > + } > +#endif Could we tuck this away into "elants_acpi_is_hid_device" and have #ifdef protecting that and have a complementing stub? > + > if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > dev_err(&client->dev, > "%s: i2c check functionality error\n", DEVICE_NAME); As a cleanup should probably drop device prefix from this message as well. Thanks. -- Dmitry
