1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 60779ebf2ff6..959109609d85 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -979,6 +979,7 @@ static int sky2_rx_start(struct sky2_port *sky2)
         struct sky2_hw *hw = sky2->hw;
         unsigned rxq = rxqaddr[sky2->port];
         int i;
+        unsigned thresh;
 
         sky2->rx_put = sky2->rx_next = 0;
         sky2_qset(hw, rxq);
@@ -1003,9 +1004,21 @@ static int sky2_rx_start(struct sky2_port *sky2)
                 sky2_rx_add(sky2, re->mapaddr);
         }
 
-        /* Truncate oversize frames */
-        sky2_write16(hw, SK_REG(sky2->port, RX_GMF_TR_THR), sky2->rx_bufsize - 8);
-        sky2_write32(hw, SK_REG(sky2->port, RX_GMF_CTRL_T), RX_TRUNC_ON);
+
+        /*
+         * The receiver hangs if it receives frames larger than the
+         * packet buffer. As a workaround, truncate oversize frames, but
+         * the register is limited to 9 bits, so if you do frames > 2052
+         * you better get the MTU right!
+         */
+        thresh = (sky2->rx_bufsize - 8) / sizeof(u32);
+        if (thresh > 0x1ff)
+                sky2_write32(hw, SK_REG(sky2->port, RX_GMF_CTRL_T), RX_TRUNC_OFF);
+        else {
+                sky2_write16(hw, SK_REG(sky2->port, RX_GMF_TR_THR), thresh);
+                sky2_write32(hw, SK_REG(sky2->port, RX_GMF_CTRL_T), RX_TRUNC_ON);
+        }
+
 
         /* Tell chip about available buffers */
         sky2_write16(hw, Y2_QADDR(rxq, PREF_UNIT_PUT_IDX), sky2->rx_put);