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authorPali Rohár <pali.rohar@gmail.com>2014-11-08 12:58:57 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-21 09:23:03 -0800
commitc34120aafab9094d4bdc1f9e6838a13c6ec54159 (patch)
tree90a2865f173ad8675a2fac95c16ba47b8ae1271f
parenta5c137ad9f78cc501c94a793db9147faaff2d7b0 (diff)
Input: alps - allow up to 2 invalid packets without resetting device
commit 9d720b34c0a432639252f63012e18b0507f5b432 upstream. On some Dell Latitude laptops ALPS device or Dell EC send one invalid byte in 6 bytes ALPS packet. In this case psmouse driver enter out of sync state. It looks like that all other bytes in packets are valid and also device working properly. So there is no need to do full device reset, just need to wait for byte which match condition for first byte (start of packet). Because ALPS packets are bigger (6 or 8 bytes) default limit is small. This patch increase number of invalid bytes to size of 2 ALPS packets which psmouse driver can drop before do full reset. Resetting ALPS devices take some time and when doing reset on some Dell laptops touchpad, trackstick and also keyboard do not respond. So it is better to do it only if really necessary. Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Tested-by: Pali Rohár <pali.rohar@gmail.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/input/mouse/alps.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 873c0e024889..fdffac9f741d 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -2154,6 +2154,9 @@ int alps_init(struct psmouse *psmouse)
/* We are having trouble resyncing ALPS touchpads so disable it for now */
psmouse->resync_time = 0;
+ /* Allow 2 invalid packets without resetting device */
+ psmouse->resetafter = psmouse->pktsize * 2;
+
return 0;
init_fail: