Re: [RFC PATCH net-next v2 6/6] devlink: add overwrite mode to flash update

[Jiri Pirko <jiri@resnulli.us>]

Fri, Jul 17, 2020 at 08:35:41PM CEST, jacob.e.keller@intel.com wrote:
>A flash image may contain settings or device identifying information.
>When performing a flash update, these settings and information may
>conflict with contents already in the flash. Devices may handle this
>conflict in multiple ways.
>
>Add a new attribute to the devlink command,
>DEVLINK_ATTR_FLASH_UPDATE_OVERWRITE_MODE, which specifies how the device
>should handle these settings and fields.
>
>DEVLINK_FLASH_UPDATE_OVERWRITE_NOTHING, the default, requests that all
>settings and device identifiers within the current flash are kept. That
>is, no settings or fields will be overwritten. This is the expected
>behavior for most updates, and appears to be how all of the drivers are
>implemented today.
>
>DEVLINK_FLASH_UPDATE_OVERWRITE_SETTINGS, requests that the device
>overwrite any device settings in the flash section with the settings
>from the flash image, but to preserve identifiers such as the MAC
>address and serial identifier. This may be useful as a way to restore
>a device to known-good settings from a new flash image.
>
>DEVLINK_FLASH_UPDATE_OVERWRITE_EVERYTHING, requests that all content in
>the flash image be preserved over content of flash on the device. This
>mode requests the device to completely overwrite the flash section,
>possibly changing settings and device identifiers. The primary
>motivation is to support writing initial device identifiers during
>manufacturing. It is not expected to be necessary in normal end-user
>flash updates.
>
>For the ice driver, implement support for the overwrite mode by
>selecting the associated preservation level to request from firmware.
>
>For all other drivers that support flash update, require that the mode
>be DEVLINK_FLASH_UPDATE_OVERWRITE_NOTHING, which is the expected
>default.
>
>Update the documentation to explain the overwrite mode attribute.

This looks odd. You have a single image yet you somehow divide it
into "program" and "config" areas. We already have infra in place to
take care of this. See DEVLINK_ATTR_FLASH_UPDATE_COMPONENT.
You should have 2 components:
1) "program"
2) "config"

Then it is up to the user what he decides to flash.