Re: [PATCH] net: stmmac: mmc_core: Assign, don't add interrupt registers

From: Jesper Nilsson <jesper.nilsson@axis.com>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	Paolo Abeni <pabeni@redhat.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	<netdev@vger.kernel.org>,
	<linux-stm32@st-md-mailman.stormreply.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <kernel@axis.com>
Subject: Re: [PATCH] net: stmmac: mmc_core: Assign, don't add interrupt registers
Date: Mon, 19 Feb 2024 11:40:25 +0100	[thread overview]
Message-ID: <20240219104025.GM22484@axis.com> (raw)
In-Reply-To: <61bdd802-abe4-4544-8e48-9493a6bb99c8@gmail.com>

On Fri, Feb 16, 2024 at 09:13:51AM -0800, Florian Fainelli wrote:
> So in premise I agree with the patch, that incrementing those is not the
> right way to go about them. However these registers are currently provided
> as part of the statistics set, but they should instead be accessed via the
> register dumping method.

You mean extending the dump register code to dump the MAC Management Counter
registers that are not counters?
From what I understand it's only the Rx and Tx interrupt and interrupt mask
registers that aren't counters. Oh, and the MMC control register itself?

To be honest, I don't think their use can justify the code churn.

> In either case you will get at best a snapshot of those two registers at any
> given time and I suppose this can help diagnose a stuck RX condition, but
> not much more than that.

Yeah, their use is very doubtful. For me, they only introduce more nonsense
data in my logs.

The Rx registers looks to have been added in the first version of the MMC
back in 2011, but the Tx registers never was.
In commit 1c901a46d57 Giuseppe mentions the MMC interrupts as something to
add later (if actually useful).

So Serge's suggestion to drop the entries completely is actually quite attractive.

> Florian

/^JN - Jesper Nilsson
-- 
               Jesper Nilsson -- jesper.nilsson@axis.com