Do some memory barrier changes for safety/perfomance:
Don't need read after update to index, mmiowb() followed by read at end
of irq is sufficient.
Signed-off-by: Stephn Hemminger <[EMAIL PROTECTED]>
---
drivers/net/sky2.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
--- sky2-2.6.21.orig/drivers/net/sky2.c 2007-05-08 10:29:09.000000000 -0700
+++ sky2-2.6.21/drivers/net/sky2.c 2007-05-08 10:29:14.000000000 -0700
@@ -836,10 +836,12 @@ static inline struct tx_ring_info *tx_le
/* Update chip's next pointer */
static inline void sky2_put_idx(struct sky2_hw *hw, unsigned q, u16 idx)
{
- q = Y2_QADDR(q, PREF_UNIT_PUT_IDX);
+ /* Make sure write' to descriptors are complete before we tell hardware
*/
wmb();
- sky2_write16(hw, q, idx);
- sky2_read16(hw, q);
+ sky2_write16(hw, Y2_QADDR(q, PREF_UNIT_PUT_IDX), idx);
+
+ /* Synchronize I/O on since next processor may write to tail */
+ mmiowb();
}
@@ -971,6 +973,7 @@ stopped:
/* reset the Rx prefetch unit */
sky2_write32(hw, Y2_QADDR(rxq, PREF_UNIT_CTRL), PREF_UNIT_RST_SET);
+ mmiowb();
}
/* Clean out receive buffer area, assumes receiver hardware stopped */
@@ -1190,7 +1193,7 @@ static int sky2_rx_start(struct sky2_por
}
/* Tell chip about available buffers */
- sky2_write16(hw, Y2_QADDR(rxq, PREF_UNIT_PUT_IDX), sky2->rx_put);
+ sky2_put_idx(hw, rxq, sky2->rx_put);
return 0;
nomem:
sky2_rx_clean(sky2);
@@ -1532,6 +1535,8 @@ static void sky2_tx_complete(struct sky2
}
sky2->tx_cons = idx;
+ smp_mb();
+
if (tx_avail(sky2) > MAX_SKB_TX_LE + 4)
netif_wake_queue(dev);
}
@@ -2210,6 +2215,7 @@ force_update:
/* Fully processed status ring so clear irq */
sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
+ mmiowb();
exit_loop:
if (buf_write[0]) {
@@ -2436,6 +2442,7 @@ static int sky2_poll(struct net_device *
if (work_done < work_limit) {
netif_rx_complete(dev0);
+ /* end of interrupt, re-enables also acts as I/O
synchronization */
sky2_read32(hw, B0_Y2_SP_LISR);
return 0;
} else {
--
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
