i40e: Increase timeout when checking GLGEN_RSTAT_DEVSTATE bit

BugLink: http://bugs.launchpad.net/bugs/1547674

When linking with particular PHY types (ex: copper PHY), the amount of
time it takes for the GLGEN_RSTAT_DEVSTATE to be set increases greatly,
which can lead to a timeout and failure to load the driver.

Change-ID: If02be0dfcd7c57fdde2d5c81cd63651260cd2029
Signed-off-by: Kevin Scott <kevin.c.scott@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from net-next commit 4d7cec07)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/net/ethernet/intel/i40e/i40e_common.c

@@ -1239,7 +1239,13 @@ i40e_status i40e_pf_reset(struct i40e_hw *hw)
 	grst_del = (rd32(hw, I40E_GLGEN_RSTCTL) &
 		    I40E_GLGEN_RSTCTL_GRSTDEL_MASK) >>
 		    I40E_GLGEN_RSTCTL_GRSTDEL_SHIFT;
-	for (cnt = 0; cnt < grst_del + 10; cnt++) {
+
+	/* It can take upto 15 secs for GRST steady state.
+	 * Bump it to 16 secs max to be safe.
+	 */
+	grst_del = grst_del * 20;
+
+	for (cnt = 0; cnt < grst_del; cnt++) {
 		reg = rd32(hw, I40E_GLGEN_RSTAT);
 		if (!(reg & I40E_GLGEN_RSTAT_DEVSTATE_MASK))
 			break;