From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 6FBD91F5838; Sat, 23 Aug 2025 19:25:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755977151; cv=none; b=FMMBDzF1JZR8jDfXs0PYvyQJUbwBZw9yTZb+iVXX9VW4cSNEl67JK7ri8sWIX+/GjKSIVTEFuSw67Yuv1g1fBXdVIaB8RyTf6zoGOj9XrW+ih+QwgZqB4FAiAXamSmKDe13i3SO9BnoiuVHgkxdx0Ynp4Bas8JIIN1+m1dA8oaQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755977151; c=relaxed/simple; bh=Uapsr8IX2QllNcDkajqgEWIy98NO2HVFmKjdgXYOYT4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aSuR/XldboDL0zrTrPwOMl3BGpvpXdQP1bUYG49pwXP/aidKK9xL88kDLxJ+hE/uuOWYyko3SCTj2rmnqgcg+s7B0wu5+TSoxCJGR343+uW4b5P3joelaU1XbK6VGe4Nz+VKeLdmdRs6Xq89/TfG8MBMAQX/K4A1TTZUy/Rjgks= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=tYfZnCFZ; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="tYfZnCFZ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=IeS8ye+d+W7JjnVBouNZ/oczgVKJYQHDxAlGtmr2Ra8=; b=tYfZnCFZIyuhrzKECGNyZCQ2iU g6R88xKAJDiAqORLTpMHdNB+wWT8x+xZnoyGwDX51VZ2FtF35tKxRN5QGeM/y55RqRl50X+HnMDRs 83zqOFbnyEYN7KHQ5Eb0znDy9pvKeoSBW7KOzjM0DSFmuRVO8+AgHaS7/glJgyCDblZU=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1uptrv-005mHa-KX; Sat, 23 Aug 2025 21:25:39 +0200 Date: Sat, 23 Aug 2025 21:25:39 +0200 From: Andrew Lunn To: Shenwei Wang Cc: Wei Fang , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Clark Wang , Stanislav Fomichev , imx@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-imx@nxp.com Subject: Re: [PATCH v3 net-next 5/5] net: fec: enable the Jumbo frame support for i.MX8QM Message-ID: References: <20250823190110.1186960-1-shenwei.wang@nxp.com> <20250823190110.1186960-6-shenwei.wang@nxp.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: <20250823190110.1186960-6-shenwei.wang@nxp.com> > @@ -1278,8 +1280,16 @@ fec_restart(struct net_device *ndev) > if (fep->quirks & FEC_QUIRK_ENET_MAC) { > /* enable ENET endian swap */ > ecntl |= FEC_ECR_BYTESWP; > - /* enable ENET store and forward mode */ > - writel(FEC_TXWMRK_STRFWD, fep->hwp + FEC_X_WMRK); > + > + /* When Jumbo Frame is enabled, the FIFO may not be large enough > + * to hold an entire frame. In this case, configure the interface > + * to operate in cut-through mode, triggered by the FIFO threshold. > + * Otherwise, enable the ENET store-and-forward mode. > + */ > + if (fep->quirks & FEC_QUIRK_JUMBO_FRAME) > + writel(0xF, fep->hwp + FEC_X_WMRK); The quirk indicates the hardware is capable of jumbo frames, not that jumbo frames are enabled. Don't you need to compare the mtu with ETH_FRAME_LEN + ETH_FCS_LEN to say jumbo is enabled? Is there a counter or other indication that the FIFO experienced an underflow? Andrew