How to update column value of one table comparing other table condition

update Attendence set Att_UpdateBit='0'
where fk_Att_EmpCode   In (select pk_Emp_Code
                           from EmployeeMaster
                           where ((@ATReprs_Location='All') or (fk_Emp_LocCode=@ATReprs_Location)) and
                             ((@ATReprs_Catagory='All')or (fk_Emp_CatCode=@ATReprs_Catagory)) and
                             ((@ATReprs_Department='All') or (fk_Emp_DepCode=@ATReprs_Department)))and
                                Att_Date>=@ATreprs_Fromdate and Att_Date<=@ATreprs_Todate
    

 here i am using store procedure and i am paasing parameter  and i am updating one table column from comparing other table condition with condition .Its Working  fast only 50 employe ,,but if i update using "excel upload It will tak eso much time after it show "sql query time out " please can any one help me