1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/serial/8250_pci.c b/drivers/serial/8250_pci.c
index 94886c000d2a..864ef859be56 100644
--- a/drivers/serial/8250_pci.c
+++ b/drivers/serial/8250_pci.c
@@ -594,8 +594,8 @@ pci_default_setup(struct serial_private *priv, struct pciserial_board *board,
         else
                 offset += idx * board->uart_offset;
 
-        maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) /
-                (8 << board->reg_shift);
+        maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) >>
+                (board->reg_shift + 3);
 
         if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
                 return 1;