hi, see this code

@api.multi 
def action_save(self):
    #your code
    self.ensure_one()
    #close popup
    return {'type': 'ir.actions.act_window_close'}

<odoo>
<record id="darkroom_modal_view_form" model="ir.ui.view">
<field name="name">Darkroom Modal Wizard</field>
<field name="model">darkroom.modal</field>
<field name="arch" type="xml">
<form string="Darkroom Modal">
<header />
<sheet>
<group name="data">
<field name="image" widget="darkroom" nolabel="1"/>
</group>
</sheet>
<footer>
<button special="cancel" string="Cancel" class="pull-left"/>
<button name="action_save" type="object" string="Save" class="oe_highlight pull-right"/>
</footer>
</form>
</field>
</record>
</odoo>

class Meeting(models.Model):

  .....

     @api.multi

     def write(self, values):	

         return super(Meeting, self).write(values)