From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: [v2] USB: serial: cp210x: Fix GPIO in autosuspend From: Oliver Neukum Message-Id: <1552994106.14757.34.camel@suse.com> Date: Tue, 19 Mar 2019 12:15:06 +0100 To: Johan Hovold Cc: Loic Poulain , Greg Kroah-Hartman , Karoly Pados , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org List-ID: T24gRGksIDIwMTktMDMtMTkgYXQgMTE6MzYgKzAxMDAsIEpvaGFuIEhvdm9sZCB3cm90ZToKPiBP biBNb24sIEZlYiAxOCwgMjAxOSBhdCAxMDoxNzoxMkFNICswMTAwLCBPbGl2ZXIgTmV1a3VtIHdy b3RlOgo+ID4gT24gU28sIDIwMTktMDItMTcgYXQgMTg6NTkgKzAxMDAsIEthcm9seSBQYWRvcyB3 cm90ZToKPiA+ID4gQ3VycmVudCBHUElPIGNvZGUgaW4gY3AyMTB4IGZhaWxzIHRvIHRha2UgVVNC IGF1dG9zdXNwZW5kIGludG8gYWNjb3VudCwKPiA+ID4gbWFraW5nIGl0IHByYWN0aWNhbGx5IGlt cG9zc2libGUgdG8gdXNlIEdQSU9zIHdpdGggYXV0b3N1c3BlbmQgZW5hYmxlZAo+ID4gPiB3aXRo b3V0IHVzZXIgY29uZmlndXJhdGlvbi4gRml4IHRoaXMgbGlrZSBmb3IgZnRkaV9zaW8gaW4gYSBw cmV2aW91cyBwYXRjaC4KPiA+ID4gVGVzdGVkIG9uIGEgQ1AyMTAyTi4KPiA+IHlvdXIgcGF0Y2gg aXMgbG9va2luZyBnb29kIHRvIG1lLCBidXQgSSBhbSBhZnJhaWQgdGhlcmUgYXJlIGlzc3Vlcy4K PiA+IEhvdyBkbyB0aGUgR1BJTyBsaW5lcyBvbiB0aGUgZGV2aWNlIGludGVyYWN0IHdpdGggVVNC IHJlc2V0IGFuZCBzeXN0ZW0KPiA+IHN1c3BlbmQ/Cj4gCj4gV2hhdCB3YXMgeW91ciBjb25jZXJu IGhlcmUsIE9saXZlcj8KCklmIHlvdSBoYXZlIGEgZGV2aWNlIHJlc2V0dGluZyBvciBsb3Npbmcg cG93ZXIgKGZvciByZXNldF9yZXN1bWUpIHRoZQpHUElPIGxpbmVzIHdpbGwgcmV2ZXJ0IHRvIHRo ZSBkZWZhdWx0LiBCdXQgdGhhdCBjaGFuZ2UgaXMgbm90IHJlcG9ydGVkCnRvIHVzZXIgc3BhY2Us IGlzIGl0PwpTbyB0aGUgb3JpZ2luYWwgcGF0Y2ggaXMgY29ycmVjdCwgYnV0IHRoZXJlIGFyZSBt b3JlIHNpdHVhdGlvbnMgcmF0aGVyCnRoYW4gc3VzcGVuZCB3aGljaCBjb3VsZCB0cmlnZ2VyIHRo ZSBwcm9ibGVtLgoKCVJlZ2FyZHMKCQlPbGl2ZXIK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1ED5BC43381 for ; Tue, 19 Mar 2019 11:26:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBA182085A for ; Tue, 19 Mar 2019 11:26:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727375AbfCSL0v (ORCPT ); Tue, 19 Mar 2019 07:26:51 -0400 Received: from mx2.suse.de ([195.135.220.15]:47318 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725934AbfCSL0v (ORCPT ); Tue, 19 Mar 2019 07:26:51 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id C78CFAB76; Tue, 19 Mar 2019 11:26:49 +0000 (UTC) Message-ID: <1552994106.14757.34.camel@suse.com> Subject: Re: [PATCH v2] USB: serial: cp210x: Fix GPIO in autosuspend From: Oliver Neukum To: Johan Hovold Cc: Loic Poulain , Greg Kroah-Hartman , Karoly Pados , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Date: Tue, 19 Mar 2019 12:15:06 +0100 In-Reply-To: <20190319103659.GA3178@localhost> References: <20190217175901.3986-1-pados@pados.hu> <1550481432.11088.4.camel@suse.com> <20190319103659.GA3178@localhost> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Di, 2019-03-19 at 11:36 +0100, Johan Hovold wrote: > On Mon, Feb 18, 2019 at 10:17:12AM +0100, Oliver Neukum wrote: > > On So, 2019-02-17 at 18:59 +0100, Karoly Pados wrote: > > > Current GPIO code in cp210x fails to take USB autosuspend into account, > > > making it practically impossible to use GPIOs with autosuspend enabled > > > without user configuration. Fix this like for ftdi_sio in a previous patch. > > > Tested on a CP2102N. > > your patch is looking good to me, but I am afraid there are issues. > > How do the GPIO lines on the device interact with USB reset and system > > suspend? > > What was your concern here, Oliver? If you have a device resetting or losing power (for reset_resume) the GPIO lines will revert to the default. But that change is not reported to user space, is it? So the original patch is correct, but there are more situations rather than suspend which could trigger the problem. Regards Oliver