[PATCH 0/1][RESUBMIT] input: fix weird issue of synaptics psmouse sync lost

[PATCH 0/1][RESUBMIT] input: fix weird issue of synaptics psmouse sync lost

[James M Leddy]

We have been using this patch in Ubuntu kernels for 5 months now
without issue. Since patch author Eric Miao no longer works for us,
I'm sending to the list so that other distros can take advantage of
this.

Last we left off, the suggestion was to make this generic across the
entire range of protocols, not just synaptics. I'm against this for
two reasons. The first is that I don't want to have to ask for
additional testing (I don't have access to the machine). The second
and far more important reason is that I am afraid that this will break
other non-synaptics touchpads, and even though we have a wide range of
hardware, it is impossible to guarantee that it'll work on everything
out there. I will do it however if it's the way we need to go with
this.

Please let me know what you think, or if you need any additional
information or testing.

James M Leddy (1):
  input: fix weird issue of synaptics psmouse sync lost
    after resume

 drivers/input/mouse/synaptics.c |    2 ++
 1 file changed, 2 insertions(+)

-- 
1.7.9.5

[PATCH 1/1][RESUBMIT] input: fix weird issue of synaptics psmouse sync lost after resume

[James M Leddy]

From: Eric Miao <eric.miao@canonical.com>

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

Only the PSMOUSE_CMD_GETID seems to be significant. The
PSMOUSE_CMD_RESET_DIS is irrelevant to this issue after trying
several times.  So we have only implemented this patch to issue
the PSMOUSE_CMD_GETID so far.

Tested-by: Daniel Manrique <daniel.manrique@canonical.com>
Signed-off-by: James M Leddy <james.leddy@canonical.com>
---
 drivers/input/mouse/synaptics.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index 12d12ca..3438a9d 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -1355,6 +1355,7 @@ 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;
 
@@ -1370,6 +1371,7 @@ 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);
 
-- 
1.7.9.5

Re: [PATCH 0/1][RESUBMIT] input: fix weird issue of synaptics psmouse sync lost

[James M Leddy]

I meant to send this to linux-input

On 04/09/2013 08:30 PM, James M Leddy wrote:
> We have been using this patch in Ubuntu kernels for 5 months now
> without issue. Since patch author Eric Miao no longer works for us,
> I'm sending to the list so that other distros can take advantage of
> this.
> 
> Last we left off, the suggestion was to make this generic across the
> entire range of protocols, not just synaptics. I'm against this for
> two reasons. The first is that I don't want to have to ask for
> additional testing (I don't have access to the machine). The second
> and far more important reason is that I am afraid that this will break
> other non-synaptics touchpads, and even though we have a wide range of
> hardware, it is impossible to guarantee that it'll work on everything
> out there. I will do it however if it's the way we need to go with
> this.
> 
> Please let me know what you think, or if you need any additional
> information or testing.
> 
> James M Leddy (1):
>   input: fix weird issue of synaptics psmouse sync lost
>     after resume
> 
>  drivers/input/mouse/synaptics.c |    2 ++
>  1 file changed, 2 insertions(+)
> 

[PATCH 1/1][RESUBMIT] input: fix weird issue of synaptics psmouse sync lost after resume

[James M Leddy]

[-- Attachment #1: Type: text/plain, Size: 1976 bytes --]

From: Eric Miao <eric.miao@canonical.com>

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

Only the PSMOUSE_CMD_GETID seems to be significant. The
PSMOUSE_CMD_RESET_DIS is irrelevant to this issue after trying
several times.  So we have only implemented this patch to issue
the PSMOUSE_CMD_GETID so far.

Tested-by: Daniel Manrique <daniel.manrique@canonical.com>
Signed-off-by: James M Leddy <james.leddy@canonical.com>
---
 drivers/input/mouse/synaptics.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/input/mouse/synaptics.c
b/drivers/input/mouse/synaptics.c
index 12d12ca..3438a9d 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -1355,6 +1355,7 @@ 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;
 @@ -1370,6 +1371,7 @@ 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);
 -- 1.7.9.5




[-- Attachment #2: Attached Message Part --]
[-- Type: text/plain, Size: 0 bytes --]