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From: Ido Schimmel <idosch@idosch•org>
To: Andrew Lunn <andrew@lunn•ch>
Cc: Russell King <rmk+kernel@armlinux•org.uk>,
	Heiner Kallweit <hkallweit1@gmail•com>,
	"David S. Miller" <davem@davemloft•net>,
	netdev@vger•kernel.org, Jakub Kicinski <kuba@kernel•org>
Subject: Re: [PATCH net-next] net: sfp: add debugfs support
Date: Tue, 24 Nov 2020 10:41:51 +0200	[thread overview]
Message-ID: <20201124084151.GA722671@shredder.lan> (raw)
In-Reply-To: <20201124001431.GA2031446@lunn.ch>

On Tue, Nov 24, 2020 at 01:14:31AM +0100, Andrew Lunn wrote:
> On Mon, Nov 23, 2020 at 10:06:16PM +0000, Russell King wrote:
> > Add debugfs support to SFP so that the internal state of the SFP state
> > machines and hardware signal state can be viewed from userspace, rather
> > than having to compile a debug kernel to view state state transitions
> > in the kernel log.  The 'state' output looks like:
> > 
> > Module state: empty
> > Module probe attempts: 0 0
> > Device state: up
> > Main state: down
> > Fault recovery remaining retries: 5
> > PHY probe remaining retries: 12
> > moddef0: 0
> > rx_los: 1
> > tx_fault: 1
> > tx_disable: 1
> > 
> > Signed-off-by: Russell King <rmk+kernel@armlinux•org.uk>
> 
> Hi Russell
> 
> This looks useful. I always seem to end up recompiling the kernel,
> which as you said, this should avoid.

FWIW, another option is to use drgn [1]. Especially when the state is
queried from the kernel and not hardware. We are using that in mlxsw
[2][3].

[1] https://github.com/osandov/drgn
[2] https://github.com/Mellanox/mlxsw/blob/master/Debugging/hdroom_dump.txt
[3] https://github.com/Mellanox/mlxsw/blob/master/Debugging/hdroom_dump.py

  reply	other threads:[~2020-11-24  8:42 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-23 22:06 [PATCH net-next] net: sfp: add debugfs support Russell King
2020-11-24  0:14 ` Andrew Lunn
2020-11-24  8:41   ` Ido Schimmel [this message]
2020-11-24  9:49     ` Russell King - ARM Linux admin
2020-11-24 10:46       ` Ido Schimmel
2020-12-02 13:03         ` Russell King - ARM Linux admin
2020-12-02 16:59           ` Jakub Kicinski
2020-12-02 17:01             ` Jakub Kicinski
2020-12-07 16:06               ` Russell King - ARM Linux admin

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