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 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id ED768C83F26 for ; Wed, 30 Jul 2025 18:32:02 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.1064393.1430057 (Exim 4.92) (envelope-from ) id 1uhBaf-0008Bp-Ux; Wed, 30 Jul 2025 18:31:49 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 1064393.1430057; Wed, 30 Jul 2025 18:31:49 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uhBaf-0008Bi-SP; Wed, 30 Jul 2025 18:31:49 +0000 Received: by outflank-mailman (input) for mailman id 1064393; Wed, 30 Jul 2025 18:31:48 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1uhBad-0008BJ-Kl for xen-devel@lists.xenproject.org; Wed, 30 Jul 2025 18:31:48 +0000 Received: from mail-24417.protonmail.ch (mail-24417.protonmail.ch [109.224.244.17]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 722a1bec-6d73-11f0-a320-13f23c93f187; Wed, 30 Jul 2025 20:31:45 +0200 (CEST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 722a1bec-6d73-11f0-a320-13f23c93f187 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=proton.me; s=protonmail; t=1753900303; x=1754159503; bh=b5n73VCyaVuuG9a+By13QW5zXMlFX4yWQsKS+Efmtfo=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=YCn90DXRXMdGdAmV1wPNrYGry+5V8FV0jF5AboNKJ8y2seShkIW3ptIqOZ4Soyl4n 1i4raYBlpUql8ImR119wGKAvDi7pmc5AIuURJzkDBAu/BiKWlt8tR8goNdqVtRX5ux /AMbDYuoPrAZ8GZimgVGglBE+ucHRIoRF9OS+BiuenrUT96uPKBAjdxyP8gqWOoYWH NtpF7b2v7owGNkYB6kgGS8NN/eXR4gG9jhsvXgZjGQgj/PyjBq57pgYwHinUnRpaGT iwBWlxGM3qv8bUWwPWTi2MueDhqZYIepQmDN9/eGOKfma6Rnh/iAWcZEfE7LX8G2nA TgaOwatU4TGVQ== Date: Wed, 30 Jul 2025 18:31:39 +0000 To: Jan Beulich From: dmkhn@proton.me Cc: andrew.cooper3@citrix.com, anthony.perard@vates.tech, julien@xen.org, michal.orzel@amd.com, roger.pau@citrix.com, sstabellini@kernel.org, dmukhin@ford.com, xen-devel@lists.xenproject.org Subject: Re: [PATCH] ns16550: ensure polling timer is disarmed Message-ID: In-Reply-To: <5a4dc92b-139d-4fa5-9baf-2ebc41bba758@suse.com> References: <20250730031249.1613142-1-dmukhin@ford.com> <5a4dc92b-139d-4fa5-9baf-2ebc41bba758@suse.com> Feedback-ID: 123220910:user:proton X-Pm-Message-ID: a6072c2abc006024fcc9ec8b9d24abd8b804d628 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Wed, Jul 30, 2025 at 10:12:54AM +0200, Jan Beulich wrote: > On 30.07.2025 05:13, dmkhn@proton.me wrote: > > From: Denis Mukhin > > > > As it stands, polling timer is kept in the list of timers even after th= e > > interrupts have been enabled / polling disabled on ns16550-compatible U= ART. > > > > Ensure polling timer is removed from the timer list once UART interrupt= s are > > enabled. > > > > Signed-off-by: Denis Mukhin >=20 > Wasn't it Andrew(?) who suggested something along these lines? That would > want reflecting by a tag then. Yes, indeed. >=20 > Also, what's the real problem you want to solve here? The timer function > would be run one more time after ->intr_works is set, and then the timer > will be permanently inactive (up to a possible S3 resume). Is it being on > an inactive list an actual problem? (IOW I'd like to understand if the > change is merely cosmetic, or if there is some actual benefit.) My understanding is running polling timer one more time after the interrupt= s are enabled is the issue: if there's a pending timer when it is known the timer not needed, then the timer should be canceled. >=20 > Jan