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Message-Id: <20090730061803.C05C3526EC9@mailhub.coreip.homeip.net>
Date: Wed, 29 Jul 2009 22:44:00 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Paul Fox <pgf@...top.org>
Cc: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
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 <pgf@...top.org>
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 <pgf@...top.org>
Acked-by: Andres Salomon <dilinger@...labora.co.uk>
Signed-off-by: Dmitry Torokhov <dtor@...l.ru>
---
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)
--
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