2009-06-02 20:06:28

by Paul Fox

[permalink] [raw]
Subject: [PATCH] forced recalibration for the OLPC hgpk touchpad

The OLPC XO laptop incorporates a combination touchpad/tablet
device which unfortunately requires frequent recalibration. The
driver will force this automatically when various suspicious
behaviors are observed, and the user can recalibrate manually
(with a special keyboard sequence). There's currently no way,
however, for an external program to cause recalibration.

This patch creates a new node in /sys which, when written with '1',
will force a touchpad recalibration. No other writes (or reads)
of this node are supported.

paul

--------------------


Signed-off-by: Paul Fox <[email protected]>

diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
index a1ad2f1..e736ebd 100644
--- a/drivers/input/mouse/hgpk.c
+++ b/drivers/input/mouse/hgpk.c
@@ -369,12 +369,40 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
__PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
hgpk_show_powered, hgpk_set_powered, 0);

+static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
+ void *data, char *buf)
+{
+ return -EINVAL;
+}
+
+static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
+ const char *buf, size_t count)
+{
+ struct hgpk_data *priv = psmouse->private;
+ unsigned long value;
+ int err;
+
+ err = strict_strtoul(buf, 10, &value);
+ if (err || value != 1)
+ return -EINVAL;
+
+ psmouse_queue_work(psmouse, &priv->recalib_wq,
+ msecs_to_jiffies(1));
+
+ return count;
+}
+
+__PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
+ hgpk_trigger_recal_show, hgpk_trigger_recal, 0);
+
static void hgpk_disconnect(struct psmouse *psmouse)
{
struct hgpk_data *priv = psmouse->private;

device_remove_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
psmouse_reset(psmouse);
kfree(priv);
}
@@ -423,8 +451,18 @@ static int hgpk_register(struct psmouse *psmouse)

err = device_create_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
- if (err)
- hgpk_err(psmouse, "Failed to create sysfs attribute\n");
+ if (err) {
+ hgpk_err(psmouse, "Failed creating 'powered' sysfs node\n");
+ } else {
+ err = device_create_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
+ if (err) {
+ hgpk_err(psmouse,
+ "Failed creating 'recalibrate' sysfs node\n");
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_powered.dattr);
+ }
+ }

return err;
}



=---------------------
paul fox, [email protected]


2009-06-03 15:05:22

by Dmitry Torokhov

[permalink] [raw]
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad

Hi Paul,

On Tuesday 02 June 2009 12:47:59 [email protected] wrote:
> The OLPC XO laptop incorporates a combination touchpad/tablet
> device which unfortunately requires frequent recalibration. The
> driver will force this automatically when various suspicious
> behaviors are observed, and the user can recalibrate manually
> (with a special keyboard sequence). There's currently no way,
> however, for an external program to cause recalibration.
>
> This patch creates a new node in /sys which, when written with '1',
> will force a touchpad recalibration. No other writes (or reads)
> of this node are supported.
>


Instead of creating a new sysfs attribute maybe we should make
the touchpad recalibrate upon resume (reconnect)? Userspace can
already request reconnect via sysfs.

--
Dmitry

2009-06-04 03:58:40

by Paul Fox

[permalink] [raw]
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad

dmitry wrote:
> Hi Paul,
>
> On Tuesday 02 June 2009 12:47:59 [email protected] wrote:
> > The OLPC XO laptop incorporates a combination touchpad/tablet
> > device which unfortunately requires frequent recalibration. The
> > driver will force this automatically when various suspicious
> > behaviors are observed, and the user can recalibrate manually
> > (with a special keyboard sequence). There's currently no way,
> > however, for an external program to cause recalibration.
> >
> > This patch creates a new node in /sys which, when written with '1',
> > will force a touchpad recalibration. No other writes (or reads)
> > of this node are supported.
> >
>
>
> Instead of creating a new sysfs attribute maybe we should make
> the touchpad recalibrate upon resume (reconnect)? Userspace can
> already request reconnect via sysfs.

dmitry -- thanks for the suggestion.

i took a look, and tried it. the problem is that doing a full
reset of the touchpad takes quite a long time -- 1.1 or 1.2
seconds. recalibration deprives the user of their touchpad for
long enough as it is -- i don't think we can afford that time.
(remember that this is a workaround for bad hardware -- the XO
no longer uses this touchpad at least partly due to this very
issue, but there are enough in use that we're still trying to
improve things.)

paul
=---------------------
paul fox, [email protected]

2009-06-04 04:17:58

by Andres Salomon

[permalink] [raw]
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad

On Wed, 03 Jun 2009 23:58:33 -0400
Paul Fox <[email protected]> wrote:

> dmitry wrote:
> > Hi Paul,
> >
> > On Tuesday 02 June 2009 12:47:59 [email protected] wrote:
> > > The OLPC XO laptop incorporates a combination touchpad/tablet
> > > device which unfortunately requires frequent recalibration. The
> > > driver will force this automatically when various suspicious
> > > behaviors are observed, and the user can recalibrate manually
> > > (with a special keyboard sequence). There's currently no way,
> > > however, for an external program to cause recalibration.
> > >
> > > This patch creates a new node in /sys which, when written with
> > > '1', will force a touchpad recalibration. No other writes (or
> > > reads) of this node are supported.
> > >
> >
> >
> > Instead of creating a new sysfs attribute maybe we should make
> > the touchpad recalibrate upon resume (reconnect)? Userspace can
> > already request reconnect via sysfs.
>
> dmitry -- thanks for the suggestion.
>
> i took a look, and tried it. the problem is that doing a full
> reset of the touchpad takes quite a long time -- 1.1 or 1.2
> seconds. recalibration deprives the user of their touchpad for
> long enough as it is -- i don't think we can afford that time.
> (remember that this is a workaround for bad hardware -- the XO
> no longer uses this touchpad at least partly due to this very
> issue, but there are enough in use that we're still trying to
> improve things.)
>

I do like the idea of having a sysfs trigger for recalibrations. We've
never been successful in having the kernel driver handle recalibrations
seamlessly. Perhaps touchpad hardware screwups would be easier to
detect in userspace, given a daemon that can keep a history of the last
N touchpad coordinates?

2009-06-17 20:16:19

by Paul Fox

[permalink] [raw]
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad

hi dmitry --

have you had a chance to think any more about this? i'm open to
suggestions on implementation detail, but i think that a full
reset of the device won't really work, because of the time it
adds to the recalibration.

paul

andres wrote:
> On Wed, 03 Jun 2009 23:58:33 -0400
> Paul Fox <[email protected]> wrote:
>
> > dmitry wrote:
> > > Hi Paul,
> > >
> > > On Tuesday 02 June 2009 12:47:59 [email protected] wrote:
> > > > The OLPC XO laptop incorporates a combination touchpad/tablet
> > > > device which unfortunately requires frequent recalibration. The
> > > > driver will force this automatically when various suspicious
> > > > behaviors are observed, and the user can recalibrate manually
> > > > (with a special keyboard sequence). There's currently no way,
> > > > however, for an external program to cause recalibration.
> > > >
> > > > This patch creates a new node in /sys which, when written with
> > > > '1', will force a touchpad recalibration. No other writes (or
> > > > reads) of this node are supported.
> > > >
> > >
> > >
> > > Instead of creating a new sysfs attribute maybe we should make
> > > the touchpad recalibrate upon resume (reconnect)? Userspace can
> > > already request reconnect via sysfs.
> >
> > dmitry -- thanks for the suggestion.
> >
> > i took a look, and tried it. the problem is that doing a full
> > reset of the touchpad takes quite a long time -- 1.1 or 1.2
> > seconds. recalibration deprives the user of their touchpad for
> > long enough as it is -- i don't think we can afford that time.
> > (remember that this is a workaround for bad hardware -- the XO
> > no longer uses this touchpad at least partly due to this very
> > issue, but there are enough in use that we're still trying to
> > improve things.)
> >
>
> I do like the idea of having a sysfs trigger for recalibrations. We've
> never been successful in having the kernel driver handle recalibrations
> seamlessly. Perhaps touchpad hardware screwups would be easier to
> detect in userspace, given a daemon that can keep a history of the last
> N touchpad coordinates?

=---------------------
paul fox, [email protected]

2009-07-29 22:29:24

by Paul Fox

[permalink] [raw]
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad

this is a resubmission, in the hopes of jump-starting the merge
discussion. it was last discussed in early june of this year.

the OLPC XO laptop incorporates a combination touchpad/tablet
device which unfortunately requires frequent recalibration. the
driver will force this automatically when various suspicious
behaviors are observed, and the user can recalibrate manually
(with a special keyboard sequence). there's currently no way,
however, for an external program to cause recalibration.

this patch creates a new node in /sys which, when written with '1',
will force a touchpad recalibration. no other writes (or reads)
of this node are supported.

during the previous discussion, dmitry suggested that we instead
use the reconnect capability which is already available in /sys.
i experimented with this, and unfortunately a full reset of
the touchpad takes quite a long time -- 1.1 or 1.2 seconds.
recalibration deprives the user of their touchpad for long enough
as it is -- i don't think we can afford that time. (note
that this is a workaround for bad hardware -- the XO no longer
uses this touchpad at least partly due to this very issue, but
there are enough in use that we're still trying to improve
things.)

paul

Signed-off-by: Paul Fox <[email protected]>
Acked-by: Andres Salomon <[email protected]>

diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
index a1ad2f1..e736ebd 100644
--- a/drivers/input/mouse/hgpk.c
+++ b/drivers/input/mouse/hgpk.c
@@ -369,12 +369,40 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
__PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
hgpk_show_powered, hgpk_set_powered, 0);

+static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
+ void *data, char *buf)
+{
+ return -EINVAL;
+}
+
+static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
+ const char *buf, size_t count)
+{
+ struct hgpk_data *priv = psmouse->private;
+ unsigned long value;
+ int err;
+
+ err = strict_strtoul(buf, 10, &value);
+ if (err || value != 1)
+ return -EINVAL;
+
+ psmouse_queue_work(psmouse, &priv->recalib_wq,
+ msecs_to_jiffies(1));
+
+ return count;
+}
+
+__PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
+ hgpk_trigger_recal_show, hgpk_trigger_recal, 0);
+
static void hgpk_disconnect(struct psmouse *psmouse)
{
struct hgpk_data *priv = psmouse->private;

device_remove_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
psmouse_reset(psmouse);
kfree(priv);
}
@@ -423,8 +451,18 @@ static int hgpk_register(struct psmouse *psmouse)

err = device_create_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
- if (err)
- hgpk_err(psmouse, "Failed to create sysfs attribute\n");
+ if (err) {
+ hgpk_err(psmouse, "Failed creating 'powered' sysfs node\n");
+ } else {
+ err = device_create_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
+ if (err) {
+ hgpk_err(psmouse,
+ "Failed creating 'recalibrate' sysfs node\n");
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_powered.dattr);
+ }
+ }

return err;
}
=---------------------
paul fox, [email protected]

2009-07-30 05:44:08

by Dmitry Torokhov

[permalink] [raw]
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad

Hi Paul,

On Wed, Jul 29, 2009 at 06:08:50PM -0400, Paul Fox wrote:
> this is a resubmission, in the hopes of jump-starting the merge
> discussion. it was last discussed in early june of this year.
>
> the OLPC XO laptop incorporates a combination touchpad/tablet
> device which unfortunately requires frequent recalibration. the
> driver will force this automatically when various suspicious
> behaviors are observed, and the user can recalibrate manually
> (with a special keyboard sequence). there's currently no way,
> however, for an external program to cause recalibration.
>
> this patch creates a new node in /sys which, when written with '1',
> will force a touchpad recalibration. no other writes (or reads)
> of this node are supported.
>
> during the previous discussion, dmitry suggested that we instead
> use the reconnect capability which is already available in /sys.
> i experimented with this, and unfortunately a full reset of
> the touchpad takes quite a long time -- 1.1 or 1.2 seconds.
> recalibration deprives the user of their touchpad for long enough
> as it is -- i don't think we can afford that time. (note
> that this is a workaround for bad hardware -- the XO no longer
> uses this touchpad at least partly due to this very issue, but
> there are enough in use that we're still trying to improve
> things.)
>

Sorry, I completely forgot about this patch... I am going to apply
it, however I think that we should not be creating the attribute
if the touchpad does not support recalibration. Also, I don't see
the reason why we can't schedule recalibration immediately instead
of waiting for 1 msec.

Could you please try updated version of the patch below?

Thanks!

--
Dmitry


Input: hgpk - forced recalibration for the OLPC touchpad

From: Paul Fox <[email protected]>

The OLPC XO laptop incorporates a combination touchpad/tablet device
which unfortunately requires frequent recalibration. The driver will
force this automatically when various suspicious behaviors are
observed, and the user can recalibrate manually (with a special
keyboard sequence). There's currently no way, however, for an external
program to cause recalibration. We can not use the reconnect
capability which is already available in /sys because full reset of
the touchpad takes 1.1 - 1.2 secons which is too long.

This patch creates a new node in /sys which, when written with '1',
will force a touchpad recalibration; no other writes (or reads)
of this node are supported.

Signed-off-by: Paul Fox <[email protected]>
Acked-by: Andres Salomon <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
---

drivers/input/mouse/hgpk.c | 55 ++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 52 insertions(+), 3 deletions(-)


diff --git a/drivers/input/mouse/hgpk.c b/drivers/input/mouse/hgpk.c
index a1ad2f1..f5aa035 100644
--- a/drivers/input/mouse/hgpk.c
+++ b/drivers/input/mouse/hgpk.c
@@ -369,12 +369,46 @@ static ssize_t hgpk_set_powered(struct psmouse *psmouse, void *data,
__PSMOUSE_DEFINE_ATTR(powered, S_IWUSR | S_IRUGO, NULL,
hgpk_show_powered, hgpk_set_powered, 0);

+static ssize_t hgpk_trigger_recal_show(struct psmouse *psmouse,
+ void *data, char *buf)
+{
+ return -EINVAL;
+}
+
+static ssize_t hgpk_trigger_recal(struct psmouse *psmouse, void *data,
+ const char *buf, size_t count)
+{
+ struct hgpk_data *priv = psmouse->private;
+ unsigned long value;
+ int err;
+
+ err = strict_strtoul(buf, 10, &value);
+ if (err || value != 1)
+ return -EINVAL;
+
+ /*
+ * We queue work instead of doing recalibration right here
+ * to avoid adding locking to to hgpk_force_recalibrate()
+ * since workqueue provides serialization.
+ */
+ psmouse_queue_work(psmouse, &priv->recalib_wq, 0);
+ return count;
+}
+
+__PSMOUSE_DEFINE_ATTR(recalibrate, S_IWUSR | S_IRUGO, NULL,
+ hgpk_trigger_recal_show, hgpk_trigger_recal, 0);
+
static void hgpk_disconnect(struct psmouse *psmouse)
{
struct hgpk_data *priv = psmouse->private;

device_remove_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
+
+ if (psmouse->model >= HGPK_MODEL_C)
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
+
psmouse_reset(psmouse);
kfree(priv);
}
@@ -423,10 +457,25 @@ static int hgpk_register(struct psmouse *psmouse)

err = device_create_file(&psmouse->ps2dev.serio->dev,
&psmouse_attr_powered.dattr);
- if (err)
- hgpk_err(psmouse, "Failed to create sysfs attribute\n");
+ if (err) {
+ hgpk_err(psmouse, "Failed creating 'powered' sysfs node\n");
+ return err;
+ }

- return err;
+ /* C-series touchpads added the recalibrate command */
+ if (psmouse->model >= HGPK_MODEL_C) {
+ err = device_create_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_recalibrate.dattr);
+ if (err) {
+ hgpk_err(psmouse,
+ "Failed creating 'recalibrate' sysfs node\n");
+ device_remove_file(&psmouse->ps2dev.serio->dev,
+ &psmouse_attr_powered.dattr);
+ return err;
+ }
+ }
+
+ return 0;
}

int hgpk_init(struct psmouse *psmouse)

2009-07-30 14:37:26

by Paul Fox

[permalink] [raw]
Subject: Re: [PATCH] forced recalibration for the OLPC hgpk touchpad

hi dmitry --

dmitry wrote:
> Sorry, I completely forgot about this patch... I am going to apply
> it, however I think that we should not be creating the attribute
> if the touchpad does not support recalibration. Also, I don't see
> the reason why we can't schedule recalibration immediately instead
> of waiting for 1 msec.
>
> Could you please try updated version of the patch below?

looks and works fine. thanks!

paul
=---------------------
paul fox, [email protected]