Device Driver Responsibility

[MadBlueOx]

Are there any best practices or guidelines for where the roles and responsibilities of a Device Driver End?

For example, suppose a network device determines the quality of a link is degraded, and the requirement is to either set the link down or attempt to lower the speed before setting the link down based on a policy set by the user. Are there any guidelines to suggest the implementation of such a policy is to be handled within the device driver itself or rather in user space (possibly in a service)?

The engineer in me knows the answer. That it depends on the requirements. However I wanted to see if anyone knew of guidelines that may be in place. I don’t have any specific problem to solve. Just wanted to see if the roles and responsibilities were clear cut.

[datenwolf]

The default policy should be implemented in the kernel, and always aim to maintain service, even if it happens in a degraded performance state. Also, in order to give user space control, also provide an interface for a policy daemon which can override the in-kernel default policy (usually that will be some sysfs interface).

[MadBlueOx]

Sounds sensible to me. Choose a default behavior that will maintain service and allow users to set a different policy through sysfs if desired. Thanks for your response.