Hi, On 3/2/21 8:42 PM, Dmitry Torokhov wrote: > 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. Right, I will fix this for v2. > >> + 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? That is a good idea, I'll do that for v2. > >> + >> 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. Ack. Regards, Hans
