linux-kernel - Re: [PATCH] eeprom: at24: Change nvmem stride to 1

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2917d26e-ad37-e118-585c-a479792fbac1@lechnology.com>
Date:   Mon, 4 Dec 2017 15:22:07 -0600
From:   David Lechner <david@...hnology.com>
To:     Bartosz Golaszewski <brgl@...ev.pl>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Cc:     linux-i2c <linux-i2c@...r.kernel.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] eeprom: at24: Change nvmem stride to 1

On 12/04/2017 11:44 AM, Bartosz Golaszewski wrote:
> I can't find any documentation on what the stride config option does
> in nvmem, but looking at the code it's only used for alignment checks
> in nvmem core, so this patch should be ok. Still: I'm wondering if it
> shouldn't depend on the size of the eeprom or if we shouldn't make the
> chip you're using a special case.

I am just guessing on the usage too, but I assume it is for memory 
alignment for other types of nvmem devices that only read words (2, 4 or 
8 bytes) at a time. I don't see anything in the at24 code that says we 
can't read any arbitrary starting I2C register, so I don't think we 
should have any problems.

> 
> @David: what is the chip you're using?

Microchip 24FC128

> Is it an at24mac402 by any
> chance? Were you affected by the read problem we fixed recently[1][2]
> in at24?

No and no.

> 
> @Srinivas: any comments on that?
> 
> Thanks,
> Bartosz
> 
> [1] http://patchwork.ozlabs.org/patch/841852/
> [2] http://patchwork.ozlabs.org/patch/841876/
>