From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (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 680443644BC for ; Fri, 28 Aug 2026 09:21:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787908893; cv=none; b=QwylyJmT+CR1S7C5Lwm0UP/WpM1XspGYxgchPhkJKi+g8bVIlpQBjiplHob5JbmpncDe54G3dCDtQw9td319LB1uU69UGe5VzOtKtZBIfS9CecjM4/kXoX0vvsT6HCGUjyzKvc7X+lVn9J3Ds9gFC3ZGZhxf/1LT4gPmpHWY3UE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787908893; c=relaxed/simple; bh=NxqJ3F5F2fcQeY3OCz8eCtxPd/hh4STLXcjymWcf4KI=; h=Mime-Version:Content-Type:Date:Message-Id:From:Subject:Cc:To: References:In-Reply-To; b=sCM04QIe7dhPGZEWcpgM6xHhvzwu+J0wanJx7UeAvrEa/xGt70Mjndv+31gfjWkXdsN2M6sN7R9+NRZkJCbDSfH4Z/VKvkcfopAvnnLyHv5pXNblHTy8/iRUDokRhxwbhF62eGx7211qqPac8HP0ovtPMl1iC+ffwjF8uSEnEFY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=uMx487Ci; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="uMx487Ci" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id D43CD1A189B; Fri, 28 Aug 2026 09:21:21 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 9F01F60537; Fri, 28 Aug 2026 09:21:21 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id E90F111C78028; Fri, 28 Aug 2026 11:21:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1787908876; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=TLtk2lBHyf4laQvUhBYdFUmCeCvqgv04fPuI7JBoqdk=; b=uMx487Ci3CN9sAO4PuSX+wMlCxyJVfgtm6++wQkYdYa0HeHqEKAGhJ5V/mK+2BYL/52uND HSszgTcp4nFCq+EePbf0n+VA2ZZm+pQRegAPrAcauy1JB5xpNIl5ig3v0hzUTqFcXkT+rN bYXcVzeWDW3TtJ6iZBl6VYHpX7bHKT7HE3+F+5KhpUB+6aNYhK7nfRoimLhiT/XzemGKwt Rh6rDLezF9d4milbXTbqjlLwlzTm4PAr+nPoTxsbyMlfxdHuberb4OfyWqSF1kipgEdDn9 iQpzlkk5NJYguRDF4+sNdlOPwz8mJRFyDvQrlvsvsP5tWrcHJi33k7KhiKuBTg== Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Fri, 28 Aug 2026 11:21:12 +0200 Message-Id: From: =?utf-8?q?Th=C3=A9o_Lebrun?= Subject: Re: [PATCH net-next 1/4] net: macb: Rename MACB_CAPS_QBV to MACB_CAPS_TC Cc: , , , , , , , , To: "Karumanchi, Vineeth" , "Conor Dooley" , "Vineeth Karumanchi" X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260807095012.640223-1-vineeth.karumanchi@amd.com> <20260807095012.640223-2-vineeth.karumanchi@amd.com> <20260807-juggle-porcupine-71281d2d9041@spud> <080ab679-cd69-48ed-b96d-c515741101ba@amd.com> In-Reply-To: <080ab679-cd69-48ed-b96d-c515741101ba@amd.com> X-Last-TLS-Session-Version: TLSv1.3 On Mon Aug 10, 2026 at 12:11 PM CEST, Karumanchi, Vineeth wrote: > On 8/7/2026 11:56 PM, Th=C3=A9o Lebrun wrote: >> On Fri Aug 7, 2026 at 7:09 PM CEST, Conor Dooley wrote: >>> On Fri, Aug 07, 2026 at 03:20:09PM +0530, Vineeth Karumanchi wrote: >>>> The MACB_CAPS_QBV capability flag was originally introduced to >>>> gate TAPRIO/QBV support. However, GEM IP versions that support >>>> QBV also implement multiple TSN clauses. >>>> >>>> Replace this with a generic capability flag that can be reused >>>> by other TSN features. Rename MACB_CAPS_QBV to MACB_CAPS_TC to >>>> better reflect its role as a general traffic-class offload capability. >>> >>> I'm not convinced that this is broadly correct, whether or not there's >>> Qav support (which is what you're using the newly renamed flag for) >>> depends on an IP configuration time define that I think is independent >>> of whether or not there's Qbv support (gem_exclude_cbs). >>> >>> That said, the only platform that supports Qbv that I have the exact >>> documentation for does not disable the CBS bits. >>=20 >> EyeQ5 instances have both active qbv and cbs as well.> >> I see two ways forward: >> - MACB_CAPS_TC aggregating the two, coming from match data >> - split and use runtime-detection, see DCFG1/0x0280 bits 1 and 24 > > This was the initial plan for the QBV implementation. > > Quoting from > https://lore.kernel.org/netdev/20250814071058.3062453-3-vineeth.karumanch= i@amd.com/ > > "The 'exclude_qbv' bit in the designcfg_debug1 register varies across > MACB/GEM IP revisions, making direct probing unreliable for detecting > QBV support. This patch introduces a capability-based approach for > consistent QBV feature identification across the IP family." This is surprising to me! What's the source? Do you have AMD hardware where DCFG1-6 have diverging layouts? Thanks, -- Th=C3=A9o Lebrun, Bootlin Embedded Linux and Kernel engineering https://bootlin.com