Received-SPF: pass (google.com: domain of linux-kernel+bounces-119040-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Feedback-ID: i80c9496c:Fastmail
Date: Tue, 26 Mar 2024 14:09:12 +0100
From: Niklas =?utf-8?Q?S=C3=B6derlund?= <niklas.soderlund+renesas@ragnatech.se>
To: Paul Barker <paul.barker.ct@bp.renesas.com>
Cc: Sergey Shtylyov <s.shtylyov@omp.ru>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] net: ravb: Always process TX descriptor ring
Message-ID: <20240326130912.GF1108818@ragnatech.se>
References: <20240326083740.23364-1-paul.barker.ct@bp.renesas.com>
 <20240326093843.GD1108818@ragnatech.se>
 <7e57c68b-1d73-40e2-824a-12193e62047f@bp.renesas.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <7e57c68b-1d73-40e2-824a-12193e62047f@bp.renesas.com>

On 2024-03-26 09:54:04 +0000, Paul Barker wrote:
> On 26/03/2024 09:38, Niklas Söderlund wrote:
> > Hi Paul,
> > 
> > Thanks for your work.
> > 
> > On 2024-03-26 08:37:39 +0000, Paul Barker wrote:
> >> The TX queue should be serviced each time the poll function is called,
> >> even if the full RX work budget has been consumed. This prevents
> >> starvation of the TX queue when RX bandwidth usage is high.
> > 
> > Is this not a design decision? That the driver should prioritize Rx over 
> > Tx if there is contention. I have no opinion on if this design is good 
> > or bad, I let Sergey judge that.
> > 
> >>
> >> Fixes: a0d2f20650e8 ("Renesas Ethernet AVB PTP clock driver")
> > 
> > However, I do not think it is a bug and should not have a fixes tag.  
> > Also this fixes tag is incorrect, this points to the commit where ravb.c 
> > was renamed ravb_main.c. ravb_poll() is not touched by this commit.
> 
> Sergey identified these as bugfixes in the following emails:
>   https://lore.kernel.org/netdev/a364963f-4e4f-dba5-cb59-b2125c14e8fc@omp.ru/
>   https://lore.kernel.org/netdev/c58ab319-222b-5ab0-0924-7774a473e276@omp.ru/

I see, I missed that. I do not agree, this is not a bugfix, it changes a 
design decision and the behavior of the driver.

@Sergey: What do you think? If you feel strongly about this being a bug 
I will yield.

> 
> I got the wrong fixes tag though, it should be:
>   Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
> 
> Thanks,
> 
> -- 
> Paul Barker


-- 
Kind Regards,
Niklas Söderlund