4.19-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Tissoires benjamin.tissoires@redhat.com
commit d21ff5d7f8c397261e095393a1a8e199934720bc upstream.
The current implementation of elan_i2c is known to not support those 2 laptops.
A proper fix is to tweak both elantech and elan_i2c to transmit the correct information from PS/2, which would make a bad candidate for stable.
So to give us some time for fixing the root of the problem, disable elan_i2c for the devices we know are not behaving properly.
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1803600 Link: https://bugs.archlinux.org/task/59714 Fixes: df077237cf55 Input: elantech - detect new ICs and setup Host Notify for them
Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Benjamin Tissoires benjamin.tissoires@redhat.com Acked-by: Peter Hutterer peter.hutterer@who-t.net Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/input/mouse/elantech.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
--- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -1767,6 +1767,18 @@ static int elantech_smbus = IS_ENABLED(C module_param_named(elantech_smbus, elantech_smbus, int, 0644); MODULE_PARM_DESC(elantech_smbus, "Use a secondary bus for the Elantech device.");
+static const char * const i2c_blacklist_pnp_ids[] = { + /* + * These are known to not be working properly as bits are missing + * in elan_i2c. + */ + "LEN2131", /* ThinkPad P52 w/ NFC */ + "LEN2132", /* ThinkPad P52 */ + "LEN2133", /* ThinkPad P72 w/ NFC */ + "LEN2134", /* ThinkPad P72 */ + NULL +}; + static int elantech_create_smbus(struct psmouse *psmouse, struct elantech_device_info *info, bool leave_breadcrumbs) @@ -1802,10 +1814,12 @@ static int elantech_setup_smbus(struct p
if (elantech_smbus == ELANTECH_SMBUS_NOT_SET) { /* - * New ICs are enabled by default. + * New ICs are enabled by default, unless mentioned in + * i2c_blacklist_pnp_ids. * Old ICs are up to the user to decide. */ - if (!ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version)) + if (!ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) || + psmouse_matches_pnp_id(psmouse, i2c_blacklist_pnp_ids)) return -ENXIO; }