[PATCH] emac: fix skb allocation for full-size jumbo frames

[Matt Porter]

Sets jumbo frame handling based on MTU and allocates rx buffers
large to handle full-size jumbo frames.

Signed-off-by: Matt Porter <mporter at kernel.crashing.org>

===== drivers/net/ibm_emac/ibm_emac_core.c 1.9 vs edited =====
--- 1.9/drivers/net/ibm_emac/ibm_emac_core.c    2005-01-20 13:25:10 -07:00
+++ edited/drivers/net/ibm_emac/ibm_emac_core.c 2005-02-18 09:23:08 -07:00
@@ -1041,7 +1056,7 @@
        /* set speed (default is 10Mb) */
        switch (speed) {
        case SPEED_1000:
-               mode_reg |= EMAC_M1_JUMBO_ENABLE | EMAC_M1_RFS_16K;
+               mode_reg |= EMAC_M1_RFS_16K;
                if (fep->rgmii_dev) {
                        struct ibm_ocp_rgmii *rgmii = 
RGMII_PRIV(fep->rgmii_dev);
 
@@ -1118,6 +1133,7 @@
 {
        struct ocp_enet_private *fep = dev->priv;
        int old_mtu = dev->mtu;
+       unsigned long mode_reg;
        emac_t *emacp = fep->emacp;
        u32 em0mr0;
        int i, full;
@@ -1160,10 +1176,17 @@
                        fep->rx_skb[i] = NULL;
                }
 
-               /* Set new rx_buffer_size and advertise new mtu */
-               fep->rx_buffer_size =
-                   new_mtu + ENET_HEADER_SIZE + ENET_FCS_SIZE;
+               /* Set new rx_buffer_size, jumbo cap, and advertise new mtu */
+               mode_reg = in_be32(&emacp->em0mr1);
+               if (new_mtu > ENET_DEF_MTU_SIZE) {
+                       mode_reg |= EMAC_M1_JUMBO_ENABLE;
+                       fep->rx_buffer_size = EMAC_MAX_FRAME;
+               } else {
+                       mode_reg &= ~EMAC_M1_JUMBO_ENABLE;
+                       fep->rx_buffer_size = ENET_DEF_BUF_SIZE;
+               }
                dev->mtu = new_mtu;
+               out_be32(&emacp->em0mr1, mode_reg);
 
                /* Re-init rx skbs */
                fep->rx_slot = 0;
===== drivers/net/ibm_emac/ibm_emac_core.h 1.3 vs edited =====
--- 1.3/drivers/net/ibm_emac/ibm_emac_core.h    2005-02-08 22:24:52 -07:00
+++ edited/drivers/net/ibm_emac/ibm_emac_core.h 2005-02-18 09:30:07 -07:00
@@ -77,6 +77,8 @@
 
 #define ENET_HEADER_SIZE       14
 #define ENET_FCS_SIZE          4
+#define ENET_DEF_MTU_SIZE      1500
+#define ENET_DEF_BUF_SIZE      (ENET_DEF_MTU_SIZE + ENET_HEADER_SIZE + 
ENET_FCS_SIZE)
 #define EMAC_MIN_FRAME         64
 #define EMAC_MAX_FRAME         9018
 #define EMAC_MIN_MTU           (EMAC_MIN_FRAME - ENET_HEADER_SIZE - 
ENET_FCS_SIZE)