From 883e0e366209067e690356e58e19bb2e6693b839 Mon Sep 17 00:00:00 2001 From: Nikolai Kondrashov Date: Fri, 2 Mar 2012 22:13:58 +0200 Subject: [PATCH] HID: hid-input: allow array fields out of range Allow array field values out of range as per HID 1.11 specification, section 6.2.25: Rather than returning a single bit for each button in the group, an array returns an index in each field that corresponds to the pressed button (like keyboard scan codes). An out-of range value in and array field is considered no controls asserted. Apparently, "and" above is a typo and should be "an". This fixes at least Waltop tablet pen clicks - otherwise BTN_TOUCH is never released. The relevant part of Waltop tablet report descriptors is this: 0x09, 0x42, /* Usage (Tip Switch), */ 0x09, 0x44, /* Usage (Barrel Switch), */ 0x09, 0x46, /* Usage (Tablet Pick), */ 0x15, 0x01, /* Logical Minimum (1), */ 0x25, 0x03, /* Logical Maximum (3), */ 0x75, 0x04, /* Report Size (4), */ 0x95, 0x01, /* Report Count (1), */ 0x80, /* Input, */ This is a regression fix for commit b4b583d ("HID: be more strict when ignoring out-of-range fields"). Signed-off-by: Nikolai Kondrashov Signed-off-by: Jiri Kosina --- drivers/hid/hid-input.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 9333d692a786..627850a54d34 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -986,8 +986,13 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct return; } - /* Ignore out-of-range values as per HID specification, section 5.10 */ - if (value < field->logical_minimum || value > field->logical_maximum) { + /* + * Ignore out-of-range values as per HID specification, + * section 5.10 and 6.2.25 + */ + if ((field->flags & HID_MAIN_ITEM_VARIABLE) && + (value < field->logical_minimum || + value > field->logical_maximum)) { dbg_hid("Ignoring out-of-range value %x\n", value); return; } -- 2.20.1