public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Andrew Lunn <andrew@lunn•ch>
To: Don Bollinger <don@thebollingers•org>
Cc: 'Moshe Shemesh' <moshe@nvidia•com>,
	"'David S. Miller'" <davem@davemloft•net>,
	'Jakub Kicinski' <kuba@kernel•org>,
	'Adrian Pop' <pop.adrian61@gmail•com>,
	'Michal Kubecek' <mkubecek@suse•cz>,
	netdev@vger•kernel.org,
	'Vladyslav Tarasiuk' <vladyslavt@nvidia•com>
Subject: Re: [RFC PATCH V4 net-next 1/5] ethtool: Allow network drivers to dump arbitrary EEPROM data
Date: Tue, 23 Mar 2021 03:03:56 +0100	[thread overview]
Message-ID: <YFlMjO4ZMBCcJqQ7@lunn.ch> (raw)
In-Reply-To: <007b01d71f83$2e0538f0$8a0faad0$@thebollingers.org>

> > I don't even see a need for this. The offset should be within one 1/2
> page, of
> > one bank. So offset >= 0 and <= 127. Length is also > 0 and
> > <- 127. And offset+length is <= 127.
> 
> I like the clean approach, but...   How do you request low memory?

Duh!

I got my conditions wrong. Too focused on 1/2 pages to think that two
of them makes one page!

Lets try again:

offset < 256
0 < len < 128

if (offset < 128)
   offset + len < 128
else
   offset + len < 256

Does that look better?

Reading bytes from the lower 1/2 of page 0 should give the same data
as reading data from the lower 1/2 of page 42. So we can allow that,
but don't be too surprised when an SFP gets it wrong and gives you
rubbish. I would suggest ethtool(1) never actually does read from the
lower 1/2 of any page other than 0.

And i agree about documentation. I would suggest a comment in
ethtool_netlink.h, and the RST documentation.

		   Andrew


  reply	other threads:[~2021-03-23  2:05 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-22 17:11 [RFC PATCH V4 net-next 0/5] ethtool: Extend module EEPROM dump API Moshe Shemesh
2021-03-22 17:11 ` [RFC PATCH V4 net-next 1/5] ethtool: Allow network drivers to dump arbitrary EEPROM data Moshe Shemesh
2021-03-22 18:17   ` Don Bollinger
2021-03-23  0:27     ` Andrew Lunn
2021-03-23  1:23       ` Don Bollinger
2021-03-23  2:03         ` Andrew Lunn [this message]
2021-03-23 17:47           ` Don Bollinger
2021-03-23 22:17             ` Andrew Lunn
2021-03-24 10:14             ` Moshe Shemesh
2021-03-24 10:03       ` Moshe Shemesh
2021-03-24 12:15         ` Andrew Lunn
2021-03-23  0:54   ` Andrew Lunn
2021-03-24 10:05     ` Moshe Shemesh
2021-03-22 17:11 ` [RFC PATCH V4 net-next 2/5] net/mlx5: Refactor module EEPROM query Moshe Shemesh
2021-03-22 17:11 ` [RFC PATCH V4 net-next 3/5] net/mlx5: Implement get_module_eeprom_by_page() Moshe Shemesh
2021-03-22 17:11 ` [RFC PATCH V4 net-next 4/5] net/mlx5: Add support for DSFP module EEPROM dumps Moshe Shemesh
2021-03-22 17:11 ` [RFC PATCH V4 net-next 5/5] ethtool: Add fallback to get_module_eeprom from netlink command Moshe Shemesh

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YFlMjO4ZMBCcJqQ7@lunn.ch \
    --to=andrew@lunn$(echo .)ch \
    --cc=davem@davemloft$(echo .)net \
    --cc=don@thebollingers$(echo .)org \
    --cc=kuba@kernel$(echo .)org \
    --cc=mkubecek@suse$(echo .)cz \
    --cc=moshe@nvidia$(echo .)com \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=pop.adrian61@gmail$(echo .)com \
    --cc=vladyslavt@nvidia$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox