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);
Hi Eric,
On Sun, Jun 24, 2012 at 11:32:38PM +0800, Eric Miao wrote:
> 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.
Hmm, murky and unknown to us EC/KBC firmware code and uglies are hidden
there...
I issuing PSMOUSE_CMD_GETID bis fine if it makes some firmware happy and
we probably should do it for all protocols, not only Synaptics. Could
you please try moving calls to psmouse_reset() and psmouse_probe() in
psmouse_reconnect() up, before we check if we have protocol specific
reconnect handler?
Thanks.
--
Dmitry