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path: root/drivers/net/fs_enet/mac-fcc.c
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Diffstat (limited to 'drivers/net/fs_enet/mac-fcc.c')
-rw-r--r--drivers/net/fs_enet/mac-fcc.c49
1 files changed, 43 insertions, 6 deletions
diff --git a/drivers/net/fs_enet/mac-fcc.c b/drivers/net/fs_enet/mac-fcc.c
index 5d45084b287d..48e91b6242ce 100644
--- a/drivers/net/fs_enet/mac-fcc.c
+++ b/drivers/net/fs_enet/mac-fcc.c
@@ -504,17 +504,54 @@ static int get_regs_len(struct net_device *dev)
}
/* Some transmit errors cause the transmitter to shut
- * down. We now issue a restart transmit. Since the
- * errors close the BD and update the pointers, the restart
- * _should_ pick up without having to reset any of our
- * pointers either. Also, To workaround 8260 device erratum
- * CPM37, we must disable and then re-enable the transmitter
- * following a Late Collision, Underrun, or Retry Limit error.
+ * down. We now issue a restart transmit.
+ * Also, to workaround 8260 device erratum CPM37, we must
+ * disable and then re-enable the transmitterfollowing a
+ * Late Collision, Underrun, or Retry Limit error.
+ * In addition, tbptr may point beyond BDs beyond still marked
+ * as ready due to internal pipelining, so we need to look back
+ * through the BDs and adjust tbptr to point to the last BD
+ * marked as ready. This may result in some buffers being
+ * retransmitted.
*/
static void tx_restart(struct net_device *dev)
{
struct fs_enet_private *fep = netdev_priv(dev);
fcc_t __iomem *fccp = fep->fcc.fccp;
+ const struct fs_platform_info *fpi = fep->fpi;
+ fcc_enet_t __iomem *ep = fep->fcc.ep;
+ cbd_t __iomem *curr_tbptr;
+ cbd_t __iomem *recheck_bd;
+ cbd_t __iomem *prev_bd;
+ cbd_t __iomem *last_tx_bd;
+
+ last_tx_bd = fep->tx_bd_base + (fpi->tx_ring * sizeof(cbd_t));
+
+ /* get the current bd held in TBPTR and scan back from this point */
+ recheck_bd = curr_tbptr = (cbd_t __iomem *)
+ ((R32(ep, fen_genfcc.fcc_tbptr) - fep->ring_mem_addr) +
+ fep->ring_base);
+
+ prev_bd = (recheck_bd == fep->tx_bd_base) ? last_tx_bd : recheck_bd - 1;
+
+ /* Move through the bds in reverse, look for the earliest buffer
+ * that is not ready. Adjust TBPTR to the following buffer */
+ while ((CBDR_SC(prev_bd) & BD_ENET_TX_READY) != 0) {
+ /* Go back one buffer */
+ recheck_bd = prev_bd;
+
+ /* update the previous buffer */
+ prev_bd = (prev_bd == fep->tx_bd_base) ? last_tx_bd : prev_bd - 1;
+
+ /* We should never see all bds marked as ready, check anyway */
+ if (recheck_bd == curr_tbptr)
+ break;
+ }
+ /* Now update the TBPTR and dirty flag to the current buffer */
+ W32(ep, fen_genfcc.fcc_tbptr,
+ (uint) (((void *)recheck_bd - fep->ring_base) +
+ fep->ring_mem_addr));
+ fep->dirty_tx = recheck_bd;
C32(fccp, fcc_gfmr, FCC_GFMR_ENT);
udelay(10);