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authorBenjamin Tissoires <benjamin.tissoires@redhat.com>2019-05-21 16:38:31 +0300
committerJiri Kosina <jkosina@suse.cz>2019-05-22 13:37:37 +0300
commit81bcbad53bab4bf9f200eda303d7a05cdb9bd73b (patch)
tree76314d947dd582c731813e161c439315c98e7d95 /drivers/hid
parent69dbdfffef20c715df9f381b2cee4e9e0a4efd93 (diff)
downloadlinux-81bcbad53bab4bf9f200eda303d7a05cdb9bd73b.tar.xz
HID: multitouch: handle faulty Elo touch device
Since kernel v5.0, one single win8 touchscreen device failed. And it turns out this is because it reports 2 InRange usage per touch. It's a first, and I *really* wonder how this was allowed by Microsoft in the first place. But IIRC, Breno told me this happened *after* a firmware upgrade... Anyway, better be safe for those crappy devices, and make sure we have a full slot before jumping to the next. This won't prevent all crappy devices to fail here, but at least we will have a safeguard as long as the contact ID and the X and Y coordinates are placed in the report after the grabage. Fixes: 01eaac7e5713 ("HID: multitouch: remove one copy of values") CC: stable@vger.kernel.org # v5.0+ Reported-and-tested-by: Breno Leitao <leitao@debian.org> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid')
-rw-r--r--drivers/hid/hid-multitouch.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index c02d4cad1893..1565a307170a 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -641,6 +641,13 @@ static void mt_store_field(struct hid_device *hdev,
if (*target != DEFAULT_TRUE &&
*target != DEFAULT_FALSE &&
*target != DEFAULT_ZERO) {
+ if (usage->contactid == DEFAULT_ZERO ||
+ usage->x == DEFAULT_ZERO ||
+ usage->y == DEFAULT_ZERO) {
+ hid_dbg(hdev,
+ "ignoring duplicate usage on incomplete");
+ return;
+ }
usage = mt_allocate_usage(hdev, application);
if (!usage)
return;