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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 161DDC636CC for ; Sat, 4 Feb 2023 08:50:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:Message-ID:References:In-Reply-To:Subject:Cc:To:From:Date: MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5EkbE2y+vcbwJNNHd4DS465z4SjWr4DEGtHXtbcg2xw=; b=jSDb0ktq+HwXNpx+Yd3r27eyFW iM2E3FG+KiONNp9kUfShkRnlAJ79B8QljPYvWox5cr5wQ5gf4t7zZbs85pBQuizG66gozl7RvFpEr FqaWSBslEyUaLPd6q/MhHU2rtl3aEURT6zPbrymMPaEOpLLetqr+VTnO4kBSFFqsGUNwjQdKFu7MH Q41MgZsMzUTjp7ln+uw/nSw3I9WFY2oXXIyaUD3gRNrwlg9g/k69r8z8TlsJgpLHI5FdEyrRhAMWX Of6C3TMRBkPw/j7ZCk4yQvrAnjLn6g5n+Bpyt87PyxtDEW8d98dMIxYP8cEJv0JoLTaeXXBt3KJMI VhZMhpXA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pOEF4-004kyM-K5; Sat, 04 Feb 2023 08:49:50 +0000 Received: from [46.183.139.199] (helo=mailout-taastrup.gigahost.dk) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pOEDy-004kGY-4S; Sat, 04 Feb 2023 08:48:43 +0000 Received: from mailout.gigahost.dk (mailout.gigahost.dk [89.186.169.112]) by mailout-taastrup.gigahost.dk (Postfix) with ESMTP id 0664718839AA; Sat, 4 Feb 2023 08:48:25 +0000 (UTC) Received: from smtp.gigahost.dk (smtp.gigahost.dk [89.186.169.109]) by mailout.gigahost.dk (Postfix) with ESMTP id E1FE9250007B; Sat, 4 Feb 2023 08:48:24 +0000 (UTC) Received: by smtp.gigahost.dk (Postfix, from userid 1000) id D3B8191201E4; Sat, 4 Feb 2023 08:48:24 +0000 (UTC) X-Screener-Id: 413d8c6ce5bf6eab4824d0abaab02863e8e3f662 MIME-Version: 1.0 Date: Sat, 04 Feb 2023 09:48:24 +0100 From: netdev@kapio-technology.com To: Simon Horman Cc: Vladimir Oltean , davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, Florian Fainelli , Andrew Lunn , Eric Dumazet , Paolo Abeni , Kurt Kanzenbach , Hauke Mehrtens , Woojung Huh , "maintainer:MICROCHIP KSZ SERIES ETHERNET SWITCH DRIVER" , Sean Wang , Landen Chao , DENG Qingfang , Matthias Brugger , Claudiu Manoil , Alexandre Belloni , =?UTF-8?Q?Cl=C3=A9ment_L=C3=A9ger?= , Jiri Pirko , Ivan Vecera , Roopa Prabhu , Nikolay Aleksandrov , Russell King , Christian Marangi , open list , "moderated list:ARM/Mediatek SoC support" , "moderated list:ARM/Mediatek SoC support" , "open list:RENESAS RZ/N1 A5PSW SWITCH DRIVER" , "moderated list:ETHERNET BRIDGE" Subject: Re: [PATCH net-next 5/5] net: dsa: mv88e6xxx: implementation of dynamic ATU entries In-Reply-To: References: <20230130173429.3577450-1-netdev@kapio-technology.com> <20230130173429.3577450-6-netdev@kapio-technology.com> <9b12275969a204739ccfab972d90f20f@kapio-technology.com> <20230203204422.4wrhyathxfhj6hdt@skbuf> User-Agent: Gigahost Webmail Message-ID: <4abbe32d007240b9c3aea9c8ca936fa3@kapio-technology.com> X-Sender: netdev@kapio-technology.com Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230204_004842_347140_11D3B327 X-CRM114-Status: GOOD ( 19.19 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On 2023-02-04 09:12, Simon Horman wrote: > On Fri, Feb 03, 2023 at 10:44:22PM +0200, Vladimir Oltean wrote: >> On Fri, Feb 03, 2023 at 09:20:22AM +0100, Simon Horman wrote: >> > > else if (someflag) >> > > dosomething(); >> > > >> > > For now only one flag will actually be set and they are mutually exclusive, >> > > as they will not make sense together with the potential flags I know, but >> > > that can change at some time of course. >> > >> > Yes, I see that is workable. I do feel that checking for other flags would >> > be a bit more robust. But as you say, there are none. So whichever >> > approach you prefer is fine by me. >> >> The model we have for unsupported bits in the >> SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS >> and SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS handlers is essentially this: >> >> if (flags & ~(supported_flag_mask)) >> return -EOPNOTSUPP; >> >> if (flags & supported_flag_1) >> ... >> >> if (flags & supported_flag_2) >> ... >> >> I suppose applying this model here would address Simon's extensibility >> concern. > > Yes, that is the model I had in mind. The only thing is that we actually need to return both 0 and -EOPNOTSUPP for unsupported flags. The dynamic flag requires 0 when not supported (and supported) AFAICS. Setting a mask as 'supported' for a feature that is not really supported defeats the notion of 'supported' IMHO.