On Mon, Apr 05, 2021 at 10:27:56PM +0200, 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. > > While at it also drop the unnecessary DEVICE_NAME prefixing of the > "I2C check functionality error", dev_err already outputs the driver-name. > > Cc: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> > BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207759 > Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Applied, thank you. -- Dmitry
