I´ve following workflow rules:
W1: on Case Comment object ----action: update field on case.
W2: on case object----action: change case status
Field update on case of W1 is firing W2, I would like to avoid this cascade execution.
Do you know how?
as Thomas said in his answer it will automatically reevaluate the rules.
What you can do is add a flag on the record to stop workflow rules.
**Notes on 3 - If a workflow rule is set to reevaluate workflow rules take this into account in your workflow rule that looks at the flag - Since the workflow to set it to false only evaluates to true after the first workflow it will not cause workflows to be evaluated again when it is set to false.
Or - if you can work your workflows to evaluate properly based on themselves in isolation there will be no need for this. As an example: