HID: i2c-hid: fix i2c_hid_output_raw_report

i2c_hid_output_raw_report is used by hidraw to forward set_report requests.
The current implementation of i2c_hid_set_report needs to take the
report_id as an argument. The report_id is stored in the first byte
of the buffer in argument of i2c_hid_output_raw_report.

Not removing the report_id from the given buffer adds this byte 2 times
in the command, leading to a non working command.

Reported-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index 9ef222442ca0..5774ebf4298c 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -540,13 +540,24 @@ static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 {
         struct i2c_client *client = hid->driver_data;
         int report_id = buf[0];
+        int ret;
 
         if (report_type == HID_INPUT_REPORT)
                 return -EINVAL;
 
-        return i2c_hid_set_report(client,
+        if (report_id) {
+                buf++;
+                count--;
+        }
+
+        ret = i2c_hid_set_report(client,
                                 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
                                 report_id, buf, count);
+
+        if (report_id && ret >= 0)
+                ret++; /* add report_id to the number of transfered bytes */
+
+        return ret;
 }
 
 static int i2c_hid_parse(struct hid_device *hid)