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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 4DDDAC433E9 for ; Mon, 11 Jan 2021 08:34:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15F252251F for ; Mon, 11 Jan 2021 08:34:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727905AbhAKIeh (ORCPT ); Mon, 11 Jan 2021 03:34:37 -0500 Received: from jabberwock.ucw.cz ([46.255.230.98]:57440 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726611AbhAKIeh (ORCPT ); Mon, 11 Jan 2021 03:34:37 -0500 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 2DE6C1C0B85; Mon, 11 Jan 2021 09:33:54 +0100 (CET) Date: Mon, 11 Jan 2021 09:33:53 +0100 From: Pavel Machek To: Tony Lindgren Cc: Dmitry Torokhov , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Arthur Demchenkov , Carl Philipp Klemm , Merlijn Wajer , ruleh , Sebastian Reichel Subject: Re: [PATCH 5/5] Input: omap4-keypad - implement errata check for lost key-up events Message-ID: <20210111083353.GA23439@amd> References: <20210110190529.46135-1-tony@atomide.com> <20210110190529.46135-6-tony@atomide.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tKW2IUtsqtDRztdT" Content-Disposition: inline In-Reply-To: <20210110190529.46135-6-tony@atomide.com> User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --tKW2IUtsqtDRztdT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > We are still missing handling for errata i689 related issues for the > case where we never see a key up interrupt for the last pressed key. >=20 > To fix the issue, we must scan the key state again after the keyboard > controller has idled to check if a key up event was missed. This is > described in the omap4 silicon errata documentation for Errata ID i689 > "1.32 Keyboard Key Up Event Can Be Missed": >=20 > "When a key is released for a time shorter than the debounce time, > in-between 2 key press (KP1 and KP2), the keyboard state machine will go > to idle mode and will never detect the key release (after KP1, and also > after KP2), and thus will never generate a new IRQ indicating the key > release." >=20 > We can use PM runtime autosuspend features to check the keyboard state > after it enters idle. I thought about this and... is it reasonable? Autosuspend is now required for correct operation. But autosuspend is optional feature, configurable by user, and may not be available depending on .config. Do we need some other solution? Pavel --=20 http://www.livejournal.com/~pavelmachek --tKW2IUtsqtDRztdT Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl/8DXEACgkQMOfwapXb+vKtZACfd3NcNXkO1yKW1SP+TADKN1yG 4P4AniWJwRF37GaWLU1uCaVqN3ns6EGf =OW9c -----END PGP SIGNATURE----- --tKW2IUtsqtDRztdT--