Re: [PATCH v7 09/11] leds: trigger: netdev: add additional hardware only triggers

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Christian Marangi <ansuelsmth@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Jonathan Corbet <corbet@lwn.net>, Pavel Machek <pavel@ucw.cz>,
	John Crispin <john@phrozen.org>,
	netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-leds@vger.kernel.org, Tim Harvey <tharvey@gateworks.com>,
	Alexander Stein <alexander.stein@ew.tq-group.com>,
	Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Subject: Re: [PATCH v7 09/11] leds: trigger: netdev: add additional hardware only triggers
Date: Thu, 15 Dec 2022 17:35:47 +0000	[thread overview]
Message-ID: <Y5ta87eCAQ8XsY8L@shell.armlinux.org.uk> (raw)
In-Reply-To: <20221214235438.30271-10-ansuelsmth@gmail.com>

On Thu, Dec 15, 2022 at 12:54:36AM +0100, Christian Marangi wrote:
> Add additional hardware only triggers commonly supported by switch LEDs.
> 
> Additional modes:
> link_10: LED on with link up AND speed 10mbps
> link_100: LED on with link up AND speed 100mbps
> link_1000: LED on with link up AND speed 1000mbps
> half_duplex: LED on with link up AND half_duplex mode
> full_duplex: LED on with link up AND full duplex mode

Looking at Marvell 88e151x, I don't think this is usable there.
We have the option of supporting link_1000 on one of the LEDs,
link_100 on another, and link_10 on the other. It's rather rare
for all three leds to be wired though.

This is also a PHY where "activity" mode is supported (illuminated
or blinking if any traffic is transmitted or received) but may not
support individual directional traffic in hardware. However, it
does support forcing the LED on or off, so software mode can handle
those until the user selects a combination of modes that are
supported in the hardware.

> Additional blink interval modes:
> blink_2hz: LED blink on any even at 2Hz (250ms)
> blink_4hz: LED blink on any even at 4Hz (125ms)
> blink_8hz: LED blink on any even at 8Hz (62ms)

This seems too restrictive. For example, Marvell 88e151x supports
none of these, but does support 42, 84, 170, 340, 670ms.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!