From mboxrd@z Thu Jan 1 00:00:00 1970 From: JJ Ding Subject: Question about pass-through serio Date: Tue, 20 Sep 2011 15:06:59 +0800 Message-ID: <87wrd3pu98.fsf@emc.com.tw> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from emcscan.emc.com.tw ([192.72.220.5]:15925 "EHLO emcscan.emc.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750814Ab1ITHEO (ORCPT ); Tue, 20 Sep 2011 03:04:14 -0400 Received: from localhost ([192.168.81.59]) by emc.com.tw (8.13.7+Sun/8.13.7) with ESMTP id p8K74D9T000079 for ; Tue, 20 Sep 2011 15:04:13 +0800 (CST) Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: linux-input@vger.kernel.org Hi everyone, I am trying to understand how serio works in Linux. When reading drivers/input/mouse/synaptics.c I found a special serio type: SERIO_PS_PSTHRU. I git-grep the source tree and it seems synaptics driver is the only user of the type. I cannot find any detailed docs explaining why the synaptics driver needs this, and what's the difference between this pass-through serio and psmouse->ps2dev.serio. Can anyone help me with this? Any pointer or keyword is very much appreciated. Thank you very much. jj