[3.16.y-ckt stable] Patch "Input: usbtouchscreen - avoid unresponsive TSC-30 touch screen" has been added to staging queue
Luis Henriques
luis.henriques at canonical.com
Tue Aug 11 12:56:35 UTC 2015
This is a note to let you know that I have just added a patch titled
Input: usbtouchscreen - avoid unresponsive TSC-30 touch screen
to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue
This patch is scheduled to be released in version 3.16.7-ckt16.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Luis
------
>From 2157661d38cd2bbf98e48ce12b84b8a362f1c710 Mon Sep 17 00:00:00 2001
From: Bernhard Bender <bernhard.bender at bytecmed.com>
Date: Thu, 23 Jul 2015 13:58:08 -0700
Subject: Input: usbtouchscreen - avoid unresponsive TSC-30 touch screen
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 <jakob.mustafa at bytecmed.com>
Signed-off-by: Bernhard Bender <bernhard.bender at bytecmed.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov at gmail.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
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 a0966331a89b..c6f7e918b2b1 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -625,6 +625,9 @@ 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),
More information about the kernel-team
mailing list