From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 C5F244369A for ; Wed, 15 Apr 2026 01:19:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776215999; cv=none; b=RieBcb/Y3HZlLdR+1NiCuOPwVI8KIhAtDIv1j4UbABFGA9FjhK5R3zTI7qdhW11sw++Tgy3hB3+3zW2aO8t+4aD0gpV5QKPjT4WqDKdZgRYa2CxxmC3MeId+S4xXVrWFg1MiloPZPi4jTKqDoZH2ZcKgD1ltjhnKgs2GECU3sYs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776215999; c=relaxed/simple; bh=9DClcYz8j9nhTSC+SuTh0Gp+w7y89UTR3dD/miaI3/M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FMMdtVUFkyWI1je62Q3JIZnToI+uqMMPK7hActa3rGZ7hjWTe7+FVIpRil5geoN4CSBKLG/c/VZPSAyPdccQFg4nPDZAM03qMP5bC4LCKcrLCAmYwKnd2DXj0Ei3bDuUNfnNzQzyH8KaQplEXYneH2XB6SBqKy69/HrLjsfl4d4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=iPpV8nFr; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="iPpV8nFr" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=I9gjWrpCbTtEVvg30V7StRQdyDT0ZMhIUqhmyfKt3EI=; b=iPpV8nFrKYUIIkc1YpLGD3Xeu2 hPUHegJCV3EK6tA9b21oLvfkMtwAVWPF7+ZGS/p6oDd3uqXe0jH+gGtmaO2aJaFwBMx5ENlCY0p0N OfFPnOX/tlgkcU9FdtUQryr65LZiVeRz8z45uHH9Hp2cz197A9X/Dz0NGJvRKs3CpfZsUdv7NJPLf PenW88HFESBGqVHxH9ZY0eHMtmTRudd27RfqU9fV5TXGno9gK3vMAnhm5WGfNR5LnMOf396w56d33 zm8lcFwAPW3B+UOvrHAsG6+4427rVYRq2lCUWRWYkxoiFOijoxsC7Jf/U3U23UzT5k7gMMLfWigzi c9nUk4PA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:49420) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wCouz-000000001Ym-2IHP; Wed, 15 Apr 2026 02:19:49 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1wCouw-000000001jJ-0Fav; Wed, 15 Apr 2026 02:19:46 +0100 Date: Wed, 15 Apr 2026 02:19:45 +0100 From: "Russell King (Oracle)" To: Sam Edwards Cc: Jakub Kicinski , Andrew Lunn , Alexandre Torgue , Andrew Lunn , "David S. Miller" , Eric Dumazet , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , linux-stm32@st-md-mailman.stormreply.com, Linux Network Development Mailing List , Paolo Abeni Subject: Re: [PATCH net-next] net: stmmac: enable RPS and RBU interrupts Message-ID: References: <20260413110222.49fc3759@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: Sender: Russell King (Oracle) Okay, just a quick note to say that nvidia's 5.10.216-tegra kernel survives iperf3 -c -R to the imx6. Dumping the registers and comparing, and then forcing the RQS and TQS values to 0x23 (+1 = 36, *256 = 9216 bytes) and 0x8f (+1 = 144, *256 = 36864 ytes) respectively seems to solve the problem. Under net-next, these both end up being 0xff (+1 = 256, *256 = 65536 bytes.) Suspiciously, 36 * 4 = 144, and I also see that this kernel programs all four of the MTL receive operation mode registers, but only the first MTL transmit operation mode register. However, DMA channels 1-3 aren't initialised. net-next derives them from: unsigned int tqs = fifosz / 256 - 1; where fifosz is passed in to dwmac4_dma_tx_chan_op_mode() and unsigned int rqs = fifosz / 256 - 1; where fifosz is passed in to dwmac4_dma_rx_chan_op_mode(). Now, according to the DMA capabilities: Number of Additional RX channel: 4 Number of Additional TX channel: 4 Number of Additional RX queues: 4 Number of Additional TX queues: 4 TX Fifo Size: 65536 RX Fifo Size: 65536 However: # ethtool -l eth0 Channel parameters for eth0: Pre-set maximums: RX: 4 TX: 4 Other: 0 Combined: 0 Current hardware settings: RX: 1 TX: 1 Other: 0 Combined: 0 So, we end up allocating the entire 64K of the tx and rx FIFO to one queue in net-next. Looking back at 5.10, I don't see any code that would account for these values being programmed for TQS and RQS, it looks like the calculations are basically the same as we have today. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!