Re: [PATCH v2 net-next] lan743x: Provide Read/Write Access to on chip OTP

[David Miller <davem@davemloft.net>]

From: Bryan Whitehead <Bryan.Whitehead@microchip.com>
Date: Wed, 23 Jan 2019 15:18:47 -0500

> The LAN743x includes on chip One-Time-Programmable (OTP) memory.
> 
> This patch extends the ethtool EEPROM read/write interface to
> access OTP memory space.
> 
> The currently existing interface is limited, as it does not
> allow OTP read, and OTP writes are restricted to
> offset==0, length==512, and data[0]==0xF3.
> 
> This patch removes these restrictions and adds a private flag
> called OTP_ACCESS, which is used to switch between EEPROM, and
> OTP modes.
> 
> The private flag OTP_ACCESS is configurable through the
>   ethtool --set-priv-flags command.
> And visible through the
>   ethtool --show-priv-flags command.
> 
> By default OTP_ACCESS is false, and there for previously existing
> EEPROM commands will work exactly the same. However now access to
> OTP requires one extra step of setting OTP_ACCESS to true. This
> flag controls the read, write, and length reporting, functions
> of ethtool.
> 
> EEPROM presence is not checked when setting or clearing this flag.
> If the EEPROM is not present, the user, as before, will need to
> diagnose that using existing read and write function of ethtool,
> while OTP_ACCESS is false.
> 
> Updates for V2:
> Added comments as to why this patch is needed.
> Added comments explaining that EEPROM presence is not check
>   when setting or clearing the OTP_ACCESS flag.
> Added length checking to all otp/eeprom read/write functions.
> 
> Signed-off-by: Bryan Whitehead <Bryan.Whitehead@microchip.com>

Applied, thanks.