In the Argalastotra of Sri Srri Chandi (which is a part of the Markandeya Purana) we get:
कृष्णेन संस्तुते देवि शश्वद्भक्त्या सदाम्विके
Meaning : O Goddess! Lord Krishna worshipped you regularly with extreme devotion.
The rishi of this mantra is Vishnu Himself.
My question is: Is there any reference in our holy scriptures of Lord Krishna or Vishnu regularly worshipping the Mother Goddess?