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 3CDD8301465 for ; Wed, 11 Mar 2026 20:52:03 +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=1773262325; cv=none; b=QY0REsWKAFZ65Z8SVUV+2ZC73urH6tWV6cNLOfh7fMc4DSKGIbQtT/wFO5a8Yi3+peJEydnOnvQbqP8XWvHBt41umdXb2spu52Q2VIBbozEcjMJCXAG00Vhrep3N9JBotfvcDLM2GCrz03xVV5l+i9QpJu9SPk90g4YzTtfrF/U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773262325; c=relaxed/simple; bh=ScFO38GIlbs0Cjax1hMaBrK/ROUrNfJZ83yhGXwC35I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mNiVp4yBr3Cwc+3bsGgbY9hJ1uFIhLBx5eWxqwnQfR2L7wU1lZ8zm2eYRCf7LkaCq/TNbyNyL8pSe0KghSuytKDBCjsX+Nsgi7/lQwdl4SO0kPK5CUhhuJn1WXh19vlr0jal2izlBWxbdkoapouVy+vL5ythQ4tGo/fuXy2B3MQ= 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=FpHJK5D7; 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="FpHJK5D7" 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-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To: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=nC3EEV59VHc90/tf0FPOwaIrKtADzP+3bZxUQIxMwmQ=; b=FpHJK5D7KhLe7VbliorxzB6eA6 F0wvRAp7Mmz0A7oS3ZH5L084748GjUxsl0DqIk6174vwtpLCQygjrGm0GyYmHuDrASDjYM84b00o9 eZJ4YY6dgk2U/xq4fA7FGQf12DF//A1/8QPyFq+xdNxxMgivfWXav5m5FVGcoEckxLqvPs4isA+ul TIeoowBgvNl6xMMn/3FoG35GveFuY/6PJ3bNNZukGZM5bUkxHnRI4IE5Bhp06tV0kakYJtAF2u8sU QjSkE4z5+J0X/t+3XXUthnS7SBv1FZUQ3pQ73fhK2ZVbpobeylL1ws/SBYE0ridhTIRb5KRwsABBv xzulroCg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:44872) 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 1w0QXA-000000006us-0L8I; Wed, 11 Mar 2026 20:52:00 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1w0QX8-000000006ak-2Jhy; Wed, 11 Mar 2026 20:51:58 +0000 Date: Wed, 11 Mar 2026 20:51:58 +0000 From: "Russell King (Oracle)" To: Andrew Lunn Cc: Tomer Maimon , Giuseppe Cavallaro , netdev@vger.kernel.org Subject: Re: stmmac: TX stalls with head OWN=1; requiring manual DMA kick (6.12.63) Message-ID: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: Russell King (Oracle) On Wed, Mar 11, 2026 at 08:46:04PM +0100, Andrew Lunn wrote: > On Wed, Mar 11, 2026 at 08:34:36PM +0200, Tomer Maimon wrote: > > Hi Giuseppe, > > > > On kernel 6.12.63 (GMAC, normal 16‑byte TX descriptors), we observe > > brief TX stalls when sending small packets. > > You might want to look at Russell Kings patches from this week to > rework the descriptor handling. > > Also, please don't report problems on dead kernels. 6.12.76 is the > current version for the 6.12 LTS. There is a small chance your problem > has already been fixed, and you are wasting everybody's time. Yep. Not sure they'll materially affect any problem, because I try to avoid functional changes in stuff like those. What's missing from the original report is a description of the hardware. stmmac drives multiple different versions of the Synopsys IP which have significant changes between them. Which platform glue is being used, which core driver is being used (dwmac1000? dwmac4? etc.) Also what isn't mentioned is whether this is a regression, or whether it's something that has never worked. If it's a regression, which kernel version previously worked? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!