Legal Question in Landlord & Tenant Law in California

Reasonable notice must be given, with 24 hours being defined as presumed reasonable although it could be shown as not being so. But if you agreed to shorter notice or there was an emergecy, less than 24 hours is allowable. If this was the only time the landlord acted incorrectly, then it likely is not such a bad act as to void the entire contract of rental, especially if you have done similar things contrary to the lease. I would think the odds are not in your favor; you would have to show some significant damage from the improper visit, not just that you were miffed.