Received-SPF: pass (google.com: domain of linux-kernel+bounces-40618-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Fri, 26 Jan 2024 12:19:28 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: rohan.g.thomas@intel.com
Cc: esben@geanix.com, alexandre.torgue@foss.st.com, conor+dt@kernel.org,
 davem@davemloft.net, devicetree@vger.kernel.org, edumazet@google.com,
 fancer.lancer@gmail.com, joabreu@synopsys.com,
 krzysztof.kozlowski+dt@linaro.org, linux-arm-kernel@lists.infradead.org,
 linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
 mcoquelin.stm32@gmail.com, netdev@vger.kernel.org, pabeni@redhat.com,
 peppe.cavallaro@st.com, robh@kernel.org
Subject: Re: [PATCH net-next 1/2] dt-bindings: net: snps,dwmac: Time Based
 Scheduling
Message-ID: <20240126121928.48a44327@kernel.org>
In-Reply-To: <20240126173634.13162-1-rohan.g.thomas@intel.com>
References: <87msss4gtj.fsf@geanix.com>
	<20240126173634.13162-1-rohan.g.thomas@intel.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

On Sat, 27 Jan 2024 01:36:34 +0800 rohan.g.thomas@intel.com wrote:
> > The tricky part here is that the whole devicetree bindings story for the
> > stmmac driver is filled with such configuration choices. As such, it is
> > only natural to add the property you are suggesting here. I completely
> > agree. But you can also argue that it is "wrong", because it does not
> > just describe the hardware, but also a configuration choice.  
> 
> Isn't this requirement of using enhanced tx desc instead of normal tx
> desc to support TBS is specific to Synopsys IP? Switching from
> normal desc to enhanced desc at the time of tc-etf qdisc offload
> cannot be done without traffic disruption, which I don't think is
> acceptable. Since this behavior is IP specific, can we consider
> this as an OS configuration choice?

Why is traffic disruption not acceptable when TBS gets turned on?
User has to install the right qdisc to enable TBS, I presume,
installing qdiscs destroys the old ones which also leads to packet
drops.