All, BugLink: https://bugs.launchpad.net/bugs/717970 So in summary, the symptom is intermittent key events lost after resume on some machines with synaptics touchpad (seems this is synaptics _only_), and key events loss is due to serio port reconnect after psmouse sync lost. Removing psmouse and inserting it back during the suspend/resume process is able to work around the issue, so the difference between psmouse_connect() and psmouse_reconnect() is the key to the root cause of this problem. After comparing the two different paths, synaptics driver has its own implementation of synaptics_reconnect(), and the missing psmouse_probe() seems significant, the patch below added psmouse_probe() to the reconnect process, and has been verified many times that the issue could not be reliably reproduced. There are two PS/2 commands in psmouse_probe(): 1. PSMOUSE_CMD_GETID 2. PSMOUSE_CMD_RESET_DIS The weird thing is, the PSMOUSE_CMD_GETID seems to be significant, and the PSMOUSE_CMD_RESET_DIS is irrelevant to this issue after trying several times. Now it's rather difficult to form a sane theory. So this patch is really for RFC. Note it does fix a real problem though. ========= >8 ========= diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c index 8eac3b7..7a72d82 100644 --- a/drivers/input/mouse/synaptics.c +++ b/drivers/input/mouse/synaptics.c @@ -1218,6 +1218,7 @@ static int synaptics_reconnect(struct psmouse *psmouse) { struct synaptics_data *priv = psmouse->private; struct synaptics_data old_priv = *priv; + unsigned char param[2]; int retry = 0; int error; @@ -1233,6 +1234,7 @@ static int synaptics_reconnect(struct psmouse *psmouse) */ ssleep(1); } + ps2_command(&psmouse->ps2dev, param, PSMOUSE_CMD_GETID); error = synaptics_detect(psmouse, 0); } while (error && ++retry < 3); -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
