Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755394AbbBTVb0 (ORCPT ); Fri, 20 Feb 2015 16:31:26 -0500 Received: from mail-qa0-f51.google.com ([209.85.216.51]:37449 "EHLO mail-qa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755082AbbBTVbY convert rfc822-to-8bit (ORCPT ); Fri, 20 Feb 2015 16:31:24 -0500 MIME-Version: 1.0 In-Reply-To: <54E7A567.5030501@dell.com> References: <1424310180-2512-1-git-send-email-mario_limonciello@dell.com> <201502202024.20741@pali> <54E79167.6070701@dell.com> <201502202141.16017@pali> <54E7A567.5030501@dell.com> Date: Fri, 20 Feb 2015 16:31:23 -0500 Message-ID: Subject: Re: [PATCH] Add a quirk for the Dell XPS 13 (2015) when in PS/2 mode. From: Benjamin Tissoires To: Mario Limonciello Cc: =?UTF-8?Q?Pali_Roh=C3=A1r?= , Dmitry Torokhov , LKML , "linux-input@vger.kernel.org" , Rob Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1965 Lines: 44 On Fri, Feb 20, 2015 at 4:21 PM, Mario Limonciello wrote: > > On 02/20/2015 02:41 PM, Pali Rohár wrote: >> [snipped] > >> There is problem with some synaptics touchpad on some laptops >> (probably not dell). Windows driver loads own firmware into >> synaptics touchpad which use different protocol (as original >> firmware in touchpad). And that loaded firmware is active until >> laptop is not shut down. When you reboot from Windows to Linux >> then linux kernel driver refuse to identify & use touchpad >> because it does not support that new firmware loaded by >> Windows... I do not know lot of about this problem, I just heard >> about it from other people. I did not see any laptop "in action". >> > Ah, so it's a special interface that's implemented in the Synaptics Windows > driver. As described above this sounds like a stop gap type solution to > resolve a field problem until the firmware can be implemented into > manufactured parts. I'd suspect that people who purchased the same model of > this computer later might run into problems without warm booting as the > firmware got updated into the manufacturer's factory. > > What is most likely happening is that the synaptics driver switches the touchpad into the i2c/hid protocol. And yes Synaptics told us that only a reset re-enables the touchpad in the PS/2 mode. Kernels 3.11 and later know how to deal with this mode (through hid-rmi), so we should not see these problems in the future unless hid-rmi is not compiled in the running kernel. Fortunately, we can deal with the Dell/Synaptics touchpads, the Lenovo ones are using SMBus, and we have never been able to talk to the devices with SMBus :( Cheers, Benjamin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/