From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 B822C2D9EED; Fri, 31 Jul 2026 01:13:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785460394; cv=none; b=QUXszDWKiwOPC2frUlX1joJAdhbjNANc6tWITxQ3ZmwjRwutmwaJLrhTlK0SEgCMwt2Ro1oI/q6ahbnl8Jc3iNWlidvq8cGC6FYViyr0L/uHoYNWTpEOhItwHEVxFiulNzESp+pCWb+dV5M9Pn0qlaXFWxJbayXdvzcBOe2byiI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785460394; c=relaxed/simple; bh=CE6IOI3Quzj896XpnUKA4zZtBLQGuZgw4J3TFCNKAYU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=BCjGS5JUA0NdnchlwbSmkiEV8pAHAildwZKKuMuXg2AnDbfJxp7NPM/kNpwBRMY+98eAEqUysil3Gi28HQ7jzYYz0MQLfHL6t7/71FKbVen95h9+1WRiu4OyCxrpePBdkP2Tv5Y6QZ49uKOLSGyNupNZp3fvUVP6ePIWt4SaIwk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Qqc4gQuv; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Qqc4gQuv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BCF3B1F000E9; Fri, 31 Jul 2026 01:13:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785460392; bh=fXaUMf0zF/5/SPQo1QC30JbpmHSlPuY+L1FVuNEI1uM=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Qqc4gQuveecgPE0dRIT711f/nXZDFkWvcOcG6wI56oPkPqcFCoFIoHCCne2OV/cn/ gzlKNMDrU5/OYDtJHDyu9TY1A8pYBArqZzzxD4Ztk1t+fyPb1fcdY3p7Wj1IvzaJvl uHDRc2vf9ozRvRFq9F5TmWI0D7XoXyu0rxR+IteIBqgolkalrAP0oOyRF6bRq4wp2o puBYjwLyfwlhtxr9gWxaeSzrZFkML5/58uLvzzmlUekkAN2iPlF4lf1QAe6+YyS/CP Qukjh7A/fCNd92txYQ+uTC8SDu0EDOpqu+cA32DXweQk/YyPIRswCim1IsKAfkalec VGEZuRwpeiBWQ== Date: Thu, 30 Jul 2026 18:13:11 -0700 From: Jakub Kicinski To: "illusion.wang" Cc: dimon.zhao@nebula-matrix.com, alvin.wang@nebula-matrix.com, sam.chen@nebula-matrix.com, netdev@vger.kernel.org, andrew+netdev@lunn.ch, corbet@lwn.net, horms@kernel.org, linux-doc@vger.kernel.org, pabeni@redhat.com, vadim.fedorenko@linux.dev, lukas.bulwahn@redhat.com, edumazet@google.com, enelsonmoore@gmail.com, skhan@linuxfoundation.org, hkallweit1@gmail.com, linux-kernel@vger.kernel.org (open list) Subject: Re: [PATCH v22 net-next 02/12] net/nebula-matrix: add core driver architecture and HW layer initialization Message-ID: <20260730181311.660d9392@kernel.org> In-Reply-To: <20260723040110.91410-3-illusion.wang@nebula-matrix.com> References: <20260723040110.91410-1-illusion.wang@nebula-matrix.com> <20260723040110.91410-3-illusion.wang@nebula-matrix.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-Transfer-Encoding: 7bit On Thu, 23 Jul 2026 12:00:54 +0800 illusion.wang wrote: > + err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); > + if (err) { > + dev_dbg(dev, "Configure DMA 64 bit mask failed, err = %d\n", > + err); > + dma_32_err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); > + if (dma_32_err) { Read the documentation for the DMA API, dma_set_mask_and_coherent() is guaranteed to succeed in some cases..