[PATCH 3.13.y-ckt 22/60] Input: usbtouchscreen - avoid unresponsive TSC-30 touch screen

[Kamal Mostafa]

3.13.11-ckt26 -stable review patch.  If anyone has any objections, please let 
me know.

--

From: Bernhard Bender 

commit 968491709e5b1aaf429428814fff3d932fa90b60 upstream.

This patch fixes a problem in the usbtouchscreen driver for DMC TSC-30
touch screen.  Due to a missing delay between the RESET and SET_RATE
commands, the touch screen may become unresponsive during system startup or
driver loading.

According to the DMC documentation, a delay is needed after the RESET
command to allow the chip to complete its internal initialization. As this
delay is not guaranteed, we had a system where the touch screen
occasionally did not send any touch data. There was no other indication of
the problem.

The patch fixes the problem by adding a 150ms delay between the RESET and
SET_RATE commands.

Suggested-by: Jakob Mustafa 
Signed-off-by: Bernhard Bender 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Kamal Mostafa 
---
 drivers/input/touchscreen/usbtouchscreen.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/input/touchscreen/usbtouchscreen.c 
b/drivers/input/touchscreen/usbtouchscreen.c
index 5f87bed..20aef5d 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -626,6 +626,9 @@ static int dmc_tsc10_init(struct usbtouch_usb *usbtouch)
goto err_out;
}
 
+   /* TSC-25 data sheet specifies a delay after the RESET command */
+   msleep(150);
+
/* set coordinate output rate */
buf[0] = buf[1] = 0xFF;
ret = usb_control_msg(dev, usb_rcvctrlpipe (dev, 0),
-- 
1.9.1

--
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[PATCH 3.13.y-ckt 22/60] Input: usbtouchscreen - avoid unresponsive TSC-30 touch screen

[Kamal Mostafa]

3.13.11-ckt26 -stable review patch.  If anyone has any objections, please let 
me know.

--

From: Bernhard Bender 

commit 968491709e5b1aaf429428814fff3d932fa90b60 upstream.

This patch fixes a problem in the usbtouchscreen driver for DMC TSC-30
touch screen.  Due to a missing delay between the RESET and SET_RATE
commands, the touch screen may become unresponsive during system startup or
driver loading.

According to the DMC documentation, a delay is needed after the RESET
command to allow the chip to complete its internal initialization. As this
delay is not guaranteed, we had a system where the touch screen
occasionally did not send any touch data. There was no other indication of
the problem.

The patch fixes the problem by adding a 150ms delay between the RESET and
SET_RATE commands.

Suggested-by: Jakob Mustafa 
Signed-off-by: Bernhard Bender 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Kamal Mostafa 
---
 drivers/input/touchscreen/usbtouchscreen.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/input/touchscreen/usbtouchscreen.c 
b/drivers/input/touchscreen/usbtouchscreen.c
index 5f87bed..20aef5d 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -626,6 +626,9 @@ static int dmc_tsc10_init(struct usbtouch_usb *usbtouch)
goto err_out;
}
 
+   /* TSC-25 data sheet specifies a delay after the RESET command */
+   msleep(150);
+
/* set coordinate output rate */
buf[0] = buf[1] = 0xFF;
ret = usb_control_msg(dev, usb_rcvctrlpipe (dev, 0),
-- 
1.9.1

--
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Please read the FAQ at  http://www.tux.org/lkml/