From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F1AC617967F; Wed, 3 Jul 2024 15:03:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720019004; cv=none; b=qBxcHAjk8Lybjd6O0HUsRzxSQzRtquEFC65oLj9+BDW8ch0djz/1mNsE3ccnKiAyTZ9SODAIj4DRWn+prO1a2IZCuNX4j8RMFUrXlBuGcShJ2bRq7S9lujOo4Rs6IPxm9wJaRnEjf71761k8WLhywuxwB7e+01lULvp28ZGn/cw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720019004; c=relaxed/simple; bh=FoeiMXNWygQHXGa/435t5CfC/zmEoNiICB+QwCj3c/E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OT+UX7Ipewgt1ldfAUayQHifHvYRojQx7sP0ZHANp6kF62Wv7azKLx+O6DyZ+uDRhwvVpjqpnJq0vaePSAZsCP6jITrgHH7beIijrt8/i03XkHE8tex43n1mRsi+UGYbTcCsiaBgTxabvwI316PgwZ3a5V3QP03L+ljPxEw45yU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NcJTnO6n; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NcJTnO6n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BCD9C32781; Wed, 3 Jul 2024 15:03:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720019003; bh=FoeiMXNWygQHXGa/435t5CfC/zmEoNiICB+QwCj3c/E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NcJTnO6nmkVfC0ALn0oTGFLCMNHrRvb6GNLJW75ya9R2xkUGZvDawJi9SFlHKG0Sx aCXF2Sltzp8fBmUhkWlBVYni3OKaW5WqhaPLP2IaS6f+9Zo4NIPaxiEIjK6bmnTHmF IxsXgUsjfnKTZ/by4PY8qZbn/aoqNZUNsGZT943/Ta9EBKoORh7CFqAL8LDDjVOSmq AV4PXOljdV4Q4kmmJ5vPMryNExBmkhJoJYC/rxGT0tgcs7oYluk23dRSElR6kVaCsm qL8913WAiI6zDqk+1+ieA7zYqs8N0gLycgPp4PWiWvLardPjuBY+4o/8UOzDXzh8bU JWSWGuvVvUkSg== Date: Wed, 3 Jul 2024 16:03:18 +0100 From: Simon Horman To: Faizal Rahim Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jesse Brandeburg , Tony Nguyen , Vinicius Costa Gomes , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH iwl-net v1 2/4] igc: Fix reset adapter logics when tx mode change Message-ID: <20240703150318.GN598357@kernel.org> References: <20240702040926.3327530-1-faizal.abdul.rahim@linux.intel.com> <20240702040926.3327530-3-faizal.abdul.rahim@linux.intel.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240702040926.3327530-3-faizal.abdul.rahim@linux.intel.com> On Tue, Jul 02, 2024 at 12:09:24AM -0400, Faizal Rahim wrote: > Following the "igc: Fix TX Hang issue when QBV Gate is close" changes, > remaining issues with the reset adapter logic in igc_tsn_offload_apply() > have been observed: > > 1. The reset adapter logics for i225 and i226 differ, although they should > be the same according to the guidelines in I225/6 HW Design Section > 7.5.2.1 on software initialization during tx mode changes. > 2. The i225 resets adapter every time, even though tx mode doesn't change. > This occurs solely based on the condition igc_is_device_id_i225() when > calling schedule_work(). > 3. i226 doesn't reset adapter for tsn->legacy tx mode changes. It only > resets adapter for legacy->tsn tx mode transitions. > 4. qbv_count introduced in the patch is actually not needed; in this > context, a non-zero value of qbv_count is used to indicate if tx mode > was unconditionally set to tsn in igc_tsn_enable_offload(). This could > be replaced by checking the existing register > IGC_TQAVCTRL_TRANSMIT_MODE_TSN bit. > > This patch resolves all issues and enters schedule_work() to reset the > adapter only when changing tx mode. It also removes reliance on qbv_count. > > qbv_count field will be removed in a future patch. > > Test ran: > > 1. Verify reset adapter behaviour in i225/6: > a) Enrol a new GCL > Reset adapter observed (tx mode change legacy->tsn) > b) Enrol a new GCL without deleting qdisc > No reset adapter observed (tx mode remain tsn->tsn) > c) Delete qdisc > Reset adapter observed (tx mode change tsn->legacy) > > 2. Tested scenario from "igc: Fix TX Hang issue when QBV Gate is closed" > to confirm it remains resolved. > > Fixes: 175c241288c0 ("igc: Fix TX Hang issue when QBV Gate is closed") > Signed-off-by: Faizal Rahim Hi Faizal, Nits below not withstahdning, this looks good to me. Reviewed-by: Simon Horman > --- > drivers/net/ethernet/intel/igc/igc_tsn.c | 26 +++++++++++++++++++++--- > 1 file changed, 23 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c > index 02dd41aff634..61f047ebf34d 100644 > --- a/drivers/net/ethernet/intel/igc/igc_tsn.c > +++ b/drivers/net/ethernet/intel/igc/igc_tsn.c > @@ -49,6 +49,13 @@ static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter) > return new_flags; > } > > +static bool igc_tsn_is_tx_mode_in_tsn(struct igc_adapter *adapter) > +{ > + struct igc_hw *hw = &adapter->hw; > + > + return (bool)(rd32(IGC_TQAVCTRL) & IGC_TQAVCTRL_TRANSMIT_MODE_TSN); Perhaps it is more a question of taste than anything else. But my preference, FIIW, is to avoid casts. And I think in this case using !! is a common pattern. (Completely untested!) return !!(rd32(IGC_TQAVCTRL) & IGC_TQAVCTRL_TRANSMIT_MODE_TSN); > +} > + > void igc_tsn_adjust_txtime_offset(struct igc_adapter *adapter) > { > struct igc_hw *hw = &adapter->hw; > @@ -334,15 +341,28 @@ int igc_tsn_reset(struct igc_adapter *adapter) > return err; > } > > +static bool igc_tsn_will_tx_mode_change(struct igc_adapter *adapter) > +{ > + bool any_tsn_enabled = (bool)(igc_tsn_new_flags(adapter) & > + IGC_FLAG_TSN_ANY_ENABLED); Ditto. > + > + if ((any_tsn_enabled && !igc_tsn_is_tx_mode_in_tsn(adapter)) || > + (!any_tsn_enabled && igc_tsn_is_tx_mode_in_tsn(adapter))) > + return true; > + else > + return false; Likewise, this is probably more a matter of taste than anything else. But I think this could be expressed as: (Completely untested!) return (any_tsn_enabled && !igc_tsn_is_tx_mode_in_tsn(adapter)) || (!any_tsn_enabled && igc_tsn_is_tx_mode_in_tsn(adapter)); Similarly in the previous patch of this series. > +} > + > int igc_tsn_offload_apply(struct igc_adapter *adapter) > { > struct igc_hw *hw = &adapter->hw; > > - /* Per I225/6 HW Design Section 7.5.2.1, transmit mode > - * cannot be changed dynamically. Require reset the adapter. > + /* Per I225/6 HW Design Section 7.5.2.1 guideline, if tx mode change > + * from legacy->tsn or tsn->legacy, then reset adapter is needed. > */ > if (netif_running(adapter->netdev) && > - (igc_is_device_id_i225(hw) || !adapter->qbv_count)) { > + (igc_is_device_id_i225(hw) || igc_is_device_id_i226(hw)) && > + igc_tsn_will_tx_mode_change(adapter)) { > schedule_work(&adapter->reset_task); > return 0; > } > -- > 2.25.1 > >