From: Ido Schimmel <idosch@idosch.org>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: Andrew Lunn <andrew@lunn.ch>,
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 12:46:40 +0200 [thread overview]
Message-ID: <20201124104640.GA738122@shredder.lan> (raw)
In-Reply-To: <20201124094916.GD1551@shell.armlinux.org.uk>
On Tue, Nov 24, 2020 at 09:49:16AM +0000, Russell King - ARM Linux admin wrote:
> On Tue, Nov 24, 2020 at 10:41:51AM +0200, Ido Schimmel wrote:
> > 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].
>
> Presumably that requires /proc/kcore support, which 32-bit ARM doesn't
> have.
Yes, it does seem to be required for live debugging. I mostly work with
x86 systems, I guess it's completely different for Andrew and you.
next prev parent reply other threads:[~2020-11-24 10:47 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
2020-11-24 9:49 ` Russell King - ARM Linux admin
2020-11-24 10:46 ` Ido Schimmel [this message]
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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