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 CC28A1C68A for ; Wed, 3 Jan 2024 17:33:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qvKAO+eX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2864BC433C7; Wed, 3 Jan 2024 17:33:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1704303232; bh=prx3LNsgm9Mbd9+E7OaYCag6KGot3wmO1HUDTXTO7OA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qvKAO+eXE5+8X6EvTrnMiX5RNCaG9AdRy5c/z/KGoZukMtL8xLdgTZX8mut2Exean 7rJ0Tg4lLPhrr8irYNXrUEBT7A6nmXyo+H1anxpRREkIHtry1Dv9rHn1ol99q8CBFe /PXs3jM/cCofemzar3QR1N9qFmg2ZqB26yIo6vrovhg6sETvbxen55M4mY6AshpYn2 S0GabBziWKd7hFQgO9u6X/kq5sbBg4GKy3B5ussJYH0Xau3XtMAXik6sQLqo9bYJG5 SW38BY2ZGqL4aeslluGWd8CnA4AENfGz8IaLfQ0iUb8vOhWjX/C7WrHiXaSyuSeFMm IBYJ64cQxZyBg== Date: Wed, 3 Jan 2024 17:33:47 +0000 From: Simon Horman To: Gerhard Engleder Cc: ahmed.zaki@intel.com, netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, edumazet@google.com, pabeni@redhat.com, Jeff Guo , Jesse Brandeburg , Tony Nguyen Subject: Re: [PATCH net-next] Revert "net: ethtool: add support for symmetric-xor RSS hash" Message-ID: <20240103173347.GA72773@kernel.org> References: <20231222210000.51989-1-gerhard@engleder-embedded.com> <20231224205412.GA5962@kernel.org> 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: On Sun, Dec 24, 2023 at 11:03:29PM +0100, Gerhard Engleder wrote: > On 24.12.23 21:54, Simon Horman wrote: > > + Jeff Guo > > Jesse Brandeburg > > Tony Nguyen > > > > On Fri, Dec 22, 2023 at 10:00:00PM +0100, Gerhard Engleder wrote: > > > This reverts commit 13e59344fb9d3c9d3acd138ae320b5b67b658694. > > > > > > The tsnep driver and at least also the macb driver implement the ethtool > > > operation set_rxnfc but not the get_rxfh operation. With this commit > > > set_rxnfc returns -EOPNOTSUPP if get_rxfh is not implemented. This renders > > > set_rxnfc unuseable for drivers without get_rxfh. > > > > > > Make set_rxfnc working again for drivers without get_rxfh by reverting > > > that commit. > > > > > > Signed-off-by: Gerhard Engleder > > > > Hi Gerhard, > > > > I think it would be nice to find a way forwards that resolved > > the regression without reverting the feature. But, if that doesn't work > > out, I think the following two patches need to be reverted first in > > order to avoid breaking (x86_64 allmodconfig) builds. > > > > 352e9bf23813 ("ice: enable symmetric-xor RSS for Toeplitz hash function") > > 4a3de3fb0eb6 ("iavf: enable symmetric-xor RSS for Toeplitz hash function") > > Hi Simon, > > frist I thought about fixing, but then I was afraid that the rxfh check in > ethtool_set_rxnfc() may also affect other drivers with ethtool > get_rxfh() too. I'm not an expert in that area, so I thought it is not a > good idea to fix stuff that I don't understand and cannot test. Understood. > Taking a second look, rxfh is only checked if RXH_XFRM_SYM_XOR is set and > this flag is introduced with the same commit. So it should be safe > to do the rxfh check only if ethtool get_rxfh() is available. Thanks for taking a second look. For the record, unless I am mistaken, the revised approach has been accepted. Link: https://lore.kernel.org/all/20231226205536.32003-1-gerhard@engleder-embedded.com/