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 smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 DB40ECCF9E3 for ; Mon, 10 Nov 2025 07:43:33 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 85238813F1; Mon, 10 Nov 2025 07:43:33 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id ngEZjM7lHzNi; Mon, 10 Nov 2025 07:43:32 +0000 (UTC) X-Comment: SPF check N/A for local connections - client-ip=140.211.166.142; helo=lists1.osuosl.org; envelope-from=intel-wired-lan-bounces@osuosl.org; receiver= DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org BA644813B5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osuosl.org; s=default; t=1762760612; bh=dxRjKw1L3Vo4BvxG6c7a664xp8x6jBrMENa5cYkCAPg=; h=From:To:Cc:In-Reply-To:References:Date:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=iz9Y9RWeZtCawb8zDubkIAe6Y9MTvLyhFCDPWercZtJ13MFlX8Co/8YBt0myMiF7C tuDIT00/nvmFCUAYDIYKduHUdmBIak2rlY4xMKjqT5MPqkz4W+ZSNE0QwPF/UEGMUw RY/6coyxveOVWnTFHN62I4jqgu7Yy3MXFdfBgFiY03JdbA1sHlxCzdUJx2fGiII0D0 yVcn8MR8oAkLl8aurukSZKqd+sMp9NLxDrn/QKM4UhdsKlmmo+QC1iGA2RRtszJA5B MLkN4QTiMtxNl41cxS+KIbNVHmdxZfiVsu3VtCFJ2EWW+D8eDGKc2bJ3xLY4h43ZE5 OQU6ncXVE51lw== Received: from lists1.osuosl.org (lists1.osuosl.org [140.211.166.142]) by smtp1.osuosl.org (Postfix) with ESMTP id BA644813B5; Mon, 10 Nov 2025 07:43:32 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists1.osuosl.org (Postfix) with ESMTP id 868911CD for ; Mon, 10 Nov 2025 07:43:31 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 6C9FE608DA for ; Mon, 10 Nov 2025 07:43:31 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id NC_RNFUG4Cbn for ; Mon, 10 Nov 2025 07:43:30 +0000 (UTC) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2a0a:51c0:0:12e:550::1; helo=galois.linutronix.de; envelope-from=kurt@linutronix.de; receiver= DMARC-Filter: OpenDMARC Filter v1.4.2 smtp3.osuosl.org 86819608D9 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 86819608D9 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by smtp3.osuosl.org (Postfix) with ESMTPS id 86819608D9 for ; Mon, 10 Nov 2025 07:43:30 +0000 (UTC) From: Kurt Kanzenbach To: "Loktionov, Aleksandr" , "Nguyen, Anthony L" , "Kitszel, Przemyslaw" Cc: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Sebastian Andrzej Siewior , "Gomes, Vinicius" , "intel-wired-lan@lists.osuosl.org" , "netdev@vger.kernel.org" In-Reply-To: References: <20251107-igc_mqprio_channels-v1-1-42415562d0f8@linutronix.de> Date: Mon, 10 Nov 2025 08:43:22 +0100 Message-ID: <874ir272p1.fsf@jax.kurt.home> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1762760604; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=dxRjKw1L3Vo4BvxG6c7a664xp8x6jBrMENa5cYkCAPg=; b=srKgYrTI0WLWHg7muM/rvb2ilR0lKwIMa3Qt/uRJAfU5x9NbqS8uhIAlLxrDhB5TwWCLdK YTaKns825WFKAFIdR6pitlOvqFdgBY1bfQvC6Md5GWrwNrDWxlqW90TO7a98+t4p+zJRaY LbDLzPqkf6ZVMeUHsvbABteJi0BjmOmSuTg71+yTgcpnwx+4PJktDmKkrMWEsSNeNQ6fL2 ICjBl9eyW6QzPofyL+dGt3vnKGtyzh9SviNFNM3Rh0fryYYuLCnQ0m4xwmEMxnUUQqqtVg y0JxAOWiJXbxxM3MOIfULs/pq2mJR7TDoaroX9RUsyRYRvp/K/LhL8D+noSdOA== X-Mailman-Original-DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1762760604; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=dxRjKw1L3Vo4BvxG6c7a664xp8x6jBrMENa5cYkCAPg=; b=VkocBaG7rxb6oK4jdhPIfWEEsH/M6KQml/HczRbLUIAoD9ArEtyFJoPEbeiPWBOOnehQ1G ZuJ7TzIfQpitpOBQ== X-Mailman-Original-Authentication-Results: smtp3.osuosl.org; dmarc=pass (p=none dis=none) header.from=linutronix.de X-Mailman-Original-Authentication-Results: smtp3.osuosl.org; dkim=pass (2048-bit key, unprotected) header.d=linutronix.de header.i=@linutronix.de header.a=rsa-sha256 header.s=2020 header.b=srKgYrTI; dkim=pass header.d=linutronix.de header.i=@linutronix.de header.a=ed25519-sha256 header.s=2020e header.b=VkocBaG7 Subject: Re: [Intel-wired-lan] [PATCH iwl-next] igc: Restore default Qbv schedule when changing channels X-BeenThere: intel-wired-lan@osuosl.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Intel Wired Ethernet Linux Kernel Driver Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-wired-lan-bounces@osuosl.org Sender: "Intel-wired-lan" --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On Fri Nov 07 2025, Loktionov, Aleksandr wrote: >> -----Original Message----- >> From: Intel-wired-lan On Behalf >> Of Kurt Kanzenbach >> Sent: Friday, November 7, 2025 2:32 PM >> To: Nguyen, Anthony L ; Kitszel, >> Przemyslaw >> Cc: Andrew Lunn ; David S. Miller >> ; Eric Dumazet ; Jakub >> Kicinski ; Paolo Abeni ; Sebastian >> Andrzej Siewior ; Gomes, Vinicius >> ; intel-wired-lan@lists.osuosl.org; >> netdev@vger.kernel.org; Kurt Kanzenbach >> Subject: [Intel-wired-lan] [PATCH iwl-next] igc: Restore default Qbv >> schedule when changing channels >>=20 >> The MQPRIO (and ETF) offload utilizes the TSN Tx mode. This mode is >> always coupled to Qbv. Therefore, the driver sets a default Qbv >> schedule of all gates opened and a cycle time of 1s. This schedule is >> set during probe. >>=20 > I'd recommend to explain abbreviations in the commit message: > =E2=80=9CMulti=E2=80=91Queue Priority (MQPRIO)=E2=80=9D > =E2=80=9CEarliest TxTime First (ETF)=E2=80=9D > =E2=80=9CTime=E2=80=91Sensitive Networking (TSN)=E2=80=9D > =E2=80=9CQbv=E2=80=9D =E2=86=92 =E2=80=9CIEEE 802.1Qbv time=E2=80=91awa= re shaper (Qbv)=E2=80=9D > >> However, the following sequence of events lead to Tx issues: >>=20 >> - Boot a dual core system >> probe(): >> igc_tsn_clear_schedule(): >> -> Default Schedule is set >> Note: At this point the driver has allocated two Tx/Rx queues, >> because >> there are only two CPU(s). >>=20 >> - ethtool -L enp3s0 combined 4 >> igc_ethtool_set_channels(): >> igc_reinit_queues() >> -> Default schedule is gone, per Tx ring start and end time are >> zero >>=20 >> - tc qdisc replace dev enp3s0 handle 100 parent root mqprio \ >> num_tc 4 map 3 3 2 2 0 1 1 1 3 3 3 3 3 3 3 3 \ >> queues 1@0 1@1 1@2 1@3 hw 1 >> igc_tsn_offload_apply(): >> igc_tsn_enable_offload(): >> -> Writes zeros to IGC_STQT(i) and IGC_ENDQT(i) -> Boom >>=20 >> Therefore, restore the default Qbv schedule after changing the amount >> of channels. >>=20 >> Signed-off-by: Kurt Kanzenbach >> --- >> drivers/net/ethernet/intel/igc/igc_main.c | 2 ++ >> 1 file changed, 2 insertions(+) >>=20 >> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c >> b/drivers/net/ethernet/intel/igc/igc_main.c >> index >> 728d7ca5338bf27c3ce50a2a497b238c38cfa338..e4200fcb2682ccd5b57abb0d2b8e >> 4eb30df117df 100644 >> --- a/drivers/net/ethernet/intel/igc/igc_main.c >> +++ b/drivers/net/ethernet/intel/igc/igc_main.c >> @@ -7761,6 +7761,8 @@ int igc_reinit_queues(struct igc_adapter >> *adapter) >> if (netif_running(netdev)) >> err =3D igc_open(netdev); >>=20 >> + igc_tsn_clear_schedule(adapter); >> + > I'm afraid you need to guard the helper call on success (or when open was= n=E2=80=99t attempted) > Because call made even when igc_open() fails. > As written, igc_tsn_clear_schedule(adapter); executes unconditionally, ev= en if igc_open() > returned an error (e.g., rings not fully set up, device not ready). > That could program TSN/Qbv registers while the device is in a failed/part= ially initialized state. > Isn't it? igc_tsn_clear_schedule() does not write any registers. It just sets the default parameters. The actual programming is done later by igc_tsn_enable_offload(). 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