Avoid firmware glitch in Cypress PS/2 Trackpad firmware version 11 (as observed in Dell XPS12) which prevents driver from recognizing the trackpad.
BugLink: http://launchpad.net/bugs/1103594 Signed-off-by: Kamal Mostafa <ka...@canonical.com> Cc: Dudley Du <d...@cypress.com> --- drivers/input/mouse/cypress_ps2.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/input/mouse/cypress_ps2.c b/drivers/input/mouse/cypress_ps2.c index 1673dc6..f51765f 100644 --- a/drivers/input/mouse/cypress_ps2.c +++ b/drivers/input/mouse/cypress_ps2.c @@ -236,6 +236,13 @@ static int cypress_read_fw_version(struct psmouse *psmouse) cytp->fw_version = param[2] & FW_VERSION_MASX; cytp->tp_metrics_supported = (param[2] & TP_METRICS_MASK) ? 1 : 0; + /* + * Trackpad fw_version 11 (in Dell XPS12) yields a bogus response to + * CYTP_CMD_READ_TP_METRICS so do not try to use it. LP: #1103594. + */ + if (cytp->fw_version >= 11) + cytp->tp_metrics_supported = 0; + psmouse_dbg(psmouse, "cytp->fw_version = %d\n", cytp->fw_version); psmouse_dbg(psmouse, "cytp->tp_metrics_supported = %d\n", cytp->tp_metrics_supported); @@ -258,6 +265,9 @@ static int cypress_read_tp_metrics(struct psmouse *psmouse) cytp->tp_res_x = cytp->tp_max_abs_x / cytp->tp_width; cytp->tp_res_y = cytp->tp_max_abs_y / cytp->tp_high; + if (!cytp->tp_metrics_supported) + return 0; + memset(param, 0, sizeof(param)); if (cypress_send_ext_cmd(psmouse, CYTP_CMD_READ_TP_METRICS, param) == 0) { /* Update trackpad parameters. */ @@ -315,18 +325,15 @@ static int cypress_read_tp_metrics(struct psmouse *psmouse) static int cypress_query_hardware(struct psmouse *psmouse) { - struct cytp_data *cytp = psmouse->private; int ret; ret = cypress_read_fw_version(psmouse); if (ret) return ret; - if (cytp->tp_metrics_supported) { - ret = cypress_read_tp_metrics(psmouse); - if (ret) - return ret; - } + ret = cypress_read_tp_metrics(psmouse); + if (ret) + return ret; return 0; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
