[3.13.y.z extended stable] Patch "HID: core: do not scan constant input report" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Tue Jun 10 16:37:27 UTC 2014


This is a note to let you know that I have just added a patch titled

    HID: core: do not scan constant input report

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.3.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 5f01e815e32381ea064c47b374c6d71b7f052bf1 Mon Sep 17 00:00:00 2001
From: Benjamin Tissoires <benjamin.tissoires at redhat.com>
Date: Mon, 31 Mar 2014 13:27:10 -0400
Subject: HID: core: do not scan constant input report

commit e24d0d399b2fce71b627043e900ef28283850482 upstream.

The Microsoft Surface Type/Touch Cover 2 is a fancy device which advertised
itself as a multitouch device but with constant input reports.
This way, hid_scan_report() gives the group MULTITOUCH to it, but
hid-multitouch can not handle it due to the constant collection ignored
by hid-input.

To prevent such crap in the future, and while we do not fix this particular
device, make the scan_report coherent with hid-input.c, and ignore constant
input reports.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires at redhat.com>
Signed-off-by: Jiri Kosina <jkosina at suse.cz>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/hid/hid-core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 253fe23..12f1a45 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -718,6 +718,9 @@ static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
 	case HID_MAIN_ITEM_TAG_END_COLLECTION:
 		break;
 	case HID_MAIN_ITEM_TAG_INPUT:
+		/* ignore constant inputs, they will be ignored by hid-input */
+		if (data & HID_MAIN_ITEM_CONSTANT)
+			break;
 		for (i = 0; i < parser->local.usage_index; i++)
 			hid_scan_input_usage(parser, parser->local.usage[i]);
 		break;
--
1.9.1





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