From 9fe8eccad4425fd024516fac2ebc0a39610441a0 Mon Sep 17 00:00:00 2001 From: Fernando D S Lima Date: Thu, 3 Sep 2015 12:56:31 -0300 Subject: [PATCH] HID: sensor-hub: Fixup for Lenovo ThinkPad Helix 2 sensor hub report There is an error in the report descriptor of the Thinkpad Helix 2 where logical minimum value (557376) is greater than logical maximum (491200) for all of the magnetic flux axis data fields. This error results in a report descriptor parsing failure that causes the sensors attached to the hub not to be detected. dmesg excerpt: [ 19.866905] drivers/hid/hid-core.c: logical range invalid 0x88140 0x77ec0 [ 19.866914] hid-sensor-hub 0018:2047:0855.0007: item 0 1 0 8 parsing failed [ 19.866926] hid-sensor-hub 0018:2047:0855.0007: parse failed [ 19.866933] hid-sensor-hub: probe of 0018:2047:0855.0007 failed with error -22 Add a report fixup to change magnetic flux logical minimums to -557376 for the parsing to succeed and the sensors to get detected. After applying the fix the sensors get detected, with corresponding drivers (hid-accel-3d,hid-gyro-3d,etc) loaded, and its possible to read their values. Signed-off-by: Fernando D S Lima Reviewed-by: Srinivas Pandruvada Signed-off-by: Jiri Kosina --- drivers/hid/hid-sensor-hub.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c index a76eb2a0a987..51d51d7b2dad 100644 --- a/drivers/hid/hid-sensor-hub.c +++ b/drivers/hid/hid-sensor-hub.c @@ -593,6 +593,20 @@ static __u8 *sensor_hub_report_fixup(struct hid_device *hdev, __u8 *rdesc, } } + /* Checks if the report descriptor of Thinkpad Helix 2 has a logical + * minimum for magnetic flux axis greater than the maximum */ + if (hdev->product == USB_DEVICE_ID_TEXAS_INSTRUMENTS_LENOVO_YOGA && + *rsize == 2558 && rdesc[913] == 0x17 && rdesc[914] == 0x40 && + rdesc[915] == 0x81 && rdesc[916] == 0x08 && + rdesc[917] == 0x00 && rdesc[918] == 0x27 && + rdesc[921] == 0x07 && rdesc[922] == 0x00) { + /* Sets negative logical minimum for mag x, y and z */ + rdesc[914] = rdesc[935] = rdesc[956] = 0xc0; + rdesc[915] = rdesc[936] = rdesc[957] = 0x7e; + rdesc[916] = rdesc[937] = rdesc[958] = 0xf7; + rdesc[917] = rdesc[938] = rdesc[959] = 0xff; + } + return rdesc; } -- 2.39.5