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From: "Arthur Crépin Leblond" <arthur@marmottus.net>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] w5100: restore GPIO-based link detection
Date: Wed, 5 Aug 2026 10:25:52 +0200	[thread overview]
Message-ID: <anLzkNOBMvn7_0d3@pc-du-fromage> (raw)
In-Reply-To: <d762ff5f-30ba-42fc-bf58-500f807483ad@lunn.ch>

On Tue, Aug 04, 2026 at 07:54:29PM +0200, Andrew Lunn wrote:
>On Tue, Aug 04, 2026 at 04:38:35PM +0200, Arthur Crépin Leblond wrote:
>> Commit dacf281771a9 ("w5100: remove unused gpio link detection")
>> dropped the link_gpio/link_irq handling on the grounds that no
>> devicetree user passed a "link" GPIO at the time.
>>
>> Signed-off-by: Arthur Crépin Leblond <arthur@marmottus.net>
>
>Hi Arthur
>
>Do you understand the architecture of this device? What exactly is on
>the other end of this GPIO?
>
>https://wiznet.io/products/ethernet-chips/w5100
>
>suggests it has an integrated PHY. So why is a GPIO needed to report
>link?
>
>Thanks
>	Andrew

Hi Andrew,

the W5100/W5500 exposes directly a LINKLED pin for the carrier status.
On my board (RPi), that pin is wired to a GPIO to detect changes on the host
directly via an interrupt.

Arthur

  reply	other threads:[~2026-08-05  8:26 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-04 14:38 [PATCH] w5100: restore GPIO-based link detection Arthur Crépin Leblond
2026-08-04 15:02 ` Arnd Bergmann
2026-08-04 17:47   ` Arthur Crépin Leblond
2026-08-04 17:54 ` Andrew Lunn
2026-08-05  8:25   ` Arthur Crépin Leblond [this message]
2026-08-05  9:11     ` Arnd Bergmann
2026-08-05  9:44       ` Arthur Crépin Leblond
2026-08-05 10:46         ` Arnd Bergmann

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