2 files changed, 38 insertions, 2 deletions

diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index c52f3712ecd3..cee8ae714731 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -85,6 +85,7 @@
 #include <linux/net_tstamp.h>
 
 #include <asm/io.h>
+#include <asm/reg.h>
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 #include <linux/module.h>
@@ -928,6 +929,24 @@ static void gfar_init_filer_table(struct gfar_private *priv)
         }
 }
 
+static void gfar_detect_errata(struct gfar_private *priv)
+{
+        struct device *dev = &priv->ofdev->dev;
+        unsigned int pvr = mfspr(SPRN_PVR);
+        unsigned int svr = mfspr(SPRN_SVR);
+        unsigned int mod = (svr >> 16) & 0xfff6; /* w/o E suffix */
+        unsigned int rev = svr & 0xffff;
+
+        /* MPC8313 Rev 2.0 and higher; All MPC837x */
+        if ((pvr == 0x80850010 && mod == 0x80b0 && rev >= 0x0020) ||
+                        (pvr == 0x80861010 && (mod & 0xfff9) == 0x80c0))
+                priv->errata |= GFAR_ERRATA_74;
+
+        if (priv->errata)
+                dev_info(dev, "enabled errata workarounds, flags: 0x%x\n",
+                         priv->errata);
+}
+
 /* Set up the ethernet device structure, private data,
  * and anything else we need before we start */
 static int gfar_probe(struct of_device *ofdev,
@@ -960,6 +979,8 @@ static int gfar_probe(struct of_device *ofdev,
         dev_set_drvdata(&ofdev->dev, priv);
         regs = priv->gfargrp[0].regs;
 
+        gfar_detect_errata(priv);
+
         /* Stop the DMA engine now, in case it was running before */
         /* (The firmware could have used it, and left it running). */
         gfar_halt(dev);
@@ -974,7 +995,10 @@ static int gfar_probe(struct of_device *ofdev,
         gfar_write(&regs->maccfg1, tempval);
 
         /* Initialize MACCFG2. */
-        gfar_write(&regs->maccfg2, MACCFG2_INIT_SETTINGS);
+        tempval = MACCFG2_INIT_SETTINGS;
+        if (gfar_has_errata(priv, GFAR_ERRATA_74))
+                tempval |= MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK;
+        gfar_write(&regs->maccfg2, tempval);
 
         /* Initialize ECNTRL */
         gfar_write(&regs->ecntrl, ECNTRL_INIT_SETTINGS);
@@ -2300,7 +2324,8 @@ static int gfar_change_mtu(struct net_device *dev, int new_mtu)
          * to allow huge frames, and to check the length */
         tempval = gfar_read(&regs->maccfg2);
 
-        if (priv->rx_buffer_size > DEFAULT_RX_BUFFER_SIZE)
+        if (priv->rx_buffer_size > DEFAULT_RX_BUFFER_SIZE ||
+                        gfar_has_errata(priv, GFAR_ERRATA_74))
                 tempval |= (MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK);
         else
                 tempval &= ~(MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK);
diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index ac4a92e08c09..0a0483ce21d2 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -1025,6 +1025,10 @@ struct gfar_priv_grp {
         char int_name_er[GFAR_INT_NAME_MAX];
 };
 
+enum gfar_errata {
+        GFAR_ERRATA_74          = 0x01,
+};
+
 /* Struct stolen almost completely (and shamelessly) from the FCC enet source
  * (Ok, that's not so true anymore, but there is a family resemblence)
  * The GFAR buffer descriptors track the ring buffers.  The rx_bd_base
@@ -1049,6 +1053,7 @@ struct gfar_private {
         struct device_node *node;
         struct net_device *ndev;
         struct of_device *ofdev;
+        enum gfar_errata errata;
 
         struct gfar_priv_grp gfargrp[MAXGROUPS];
         struct gfar_priv_tx_q *tx_queue[MAX_TX_QS];
@@ -1111,6 +1116,12 @@ struct gfar_private {
 extern unsigned int ftp_rqfpr[MAX_FILER_IDX + 1];
 extern unsigned int ftp_rqfcr[MAX_FILER_IDX + 1];
 
+static inline int gfar_has_errata(struct gfar_private *priv,
+                                  enum gfar_errata err)
+{
+        return priv->errata & err;
+}
+
 static inline u32 gfar_read(volatile unsigned __iomem *addr)
 {
         u32 val;