From b2546df69b6bef19513112fd54ffb5d37cb3eb7a Mon Sep 17 00:00:00 2001 From: Arjan Opmeer Date: Sat, 18 Apr 2009 19:10:17 -0700 Subject: [PATCH] Input: elantech - make sure touchpad is really in absolute mode There exist laptops with Elantech touchpads where switching to absolute mode does not happen, although writing the configuration register succeeds without error. Reading back the register afterwards reveils that the absolute mode bit is not set as if masked out by the touchpad firmware. Always read back register 0x10, make sure that for hardware version 1 the absolute mode bit is actually set and fail otherwise. This prevents the case where the touchpad is claimed by the Elantech driver but is nonetheless not working. Signed-off-by: Arjan Opmeer Signed-off-by: Dmitry Torokhov --- drivers/input/mouse/elantech.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c index d3b591673792..4bc78892ba91 100644 --- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -375,9 +375,14 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse) rc = -1; break; } + } + + if (rc == 0) { /* - * Read back reg 0x10. The touchpad is probably initalising - * and not ready until we read back the value we just wrote. + * Read back reg 0x10. For hardware version 1 we must make + * sure the absolute mode bit is set. For hardware version 2 + * the touchpad is probably initalising and not ready until + * we read back the value we just wrote. */ do { rc = elantech_read_reg(psmouse, 0x10, &val); @@ -385,12 +390,18 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse) break; tries--; elantech_debug("elantech.c: retrying read (%d).\n", - tries); + tries); msleep(ETP_READ_BACK_DELAY); } while (tries > 0); - if (rc) + + if (rc) { pr_err("elantech.c: failed to read back register 0x10.\n"); - break; + } else if (etd->hw_version == 1 && + !(val & ETP_R10_ABSOLUTE_MODE)) { + pr_err("elantech.c: touchpad refuses " + "to switch to absolute mode.\n"); + rc = -1; + } } if (rc) -- 2.20.1