From: Andrew Lunn <andrew@lunn•ch>
To: Neil Horman <nhorman@tuxdriver•com>
Cc: Chris Preimesberger <chrisp@transition•com>,
"linville@tuxdriver•com" <linville@tuxdriver•com>,
"netdev@vger•kernel.org" <netdev@vger•kernel.org>
Subject: Re: bug: 'ethtool -m' reports spurious alarm & warning threshold values for QSFP28 transceivers
Date: Wed, 26 Sep 2018 23:58:12 +0200 [thread overview]
Message-ID: <20180926215812.GD1251@lunn.ch> (raw)
In-Reply-To: <20180926213436.GA4116@hmswarspite.think-freely.org>
> When you run ethtool -m on this driver, the kernel calls mlx4_en_get_module_info
> to determine the length of the eeprom, and that value will be either 256 or 512
> bytes.
So it sounds like QSFP modules using 8636 are not supported. You would
expect a size to be one of 256, 384, 512 or 640.
> Next it calls mlx4_en_get_module_eeprom, passing in that size 256 to actually
> read the eeprom data, which in turn calls mlx4_get_module_info to fetch the data
> from hardware, again, passing in 256 as the size for the first call (theres a
> loop, but it will only get executed once in this scenario)
>
> mlx4_get_module_info then issues the appropriate mailbox commands to dump the
> eeprom. Here it starts to go sideways. The mailbox buffer allocated for the
> return data is of type mlx4_mad_ifc, which has some front matter information and
> a data buffer that is 192 bytes long!
Which suggests all SFP dumps are broken as well, not just QSFP.
Oh dear.
Andrew
next prev parent reply other threads:[~2018-09-27 4:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-26 19:29 bug: 'ethtool -m' reports spurious alarm & warning threshold values for QSFP28 transceivers Chris Preimesberger
2018-09-26 19:44 ` Andrew Lunn
2018-09-26 20:47 ` Chris Preimesberger
2018-09-26 21:46 ` Andrew Lunn
2018-09-26 21:34 ` Neil Horman
2018-09-26 21:58 ` Andrew Lunn [this message]
2018-09-27 13:23 ` Neil Horman
2018-09-27 13:25 ` Eran Ben Elisha
2018-09-27 14:52 ` Andrew Lunn
2018-09-27 15:20 ` Eran Ben Elisha
2018-09-27 15:32 ` Andrew Lunn
2018-09-27 16:08 ` Chris Preimesberger
2018-09-27 16:38 ` Andrew Lunn
2018-09-27 18:56 ` Chris Preimesberger
2018-09-27 20:17 ` Chris Preimesberger
2018-10-02 7:10 ` Eran Ben Elisha
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